diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index effa5b12d87ac..7d23129f4b85a 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -365,6 +365,9 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.complex.cimag
     libc.src.complex.cimagf
     libc.src.complex.cimagl
+    libc.src.complex.conj
+    libc.src.complex.conjf
+    libc.src.complex.conjl
 
     # fenv.h entrypoints
     libc.src.fenv.feclearexcept
@@ -616,6 +619,7 @@ if(LIBC_TYPES_HAS_FLOAT16)
     # complex.h C23 _Complex _Float16 entrypoints
     # libc.src.complex.crealf16
     # libc.src.complex.cimagf16
+    # libc.src.complex.conjf16
     
     # math.h C23 _Float16 entrypoints
     libc.src.math.canonicalizef16
@@ -721,6 +725,7 @@ if(LIBC_TYPES_HAS_FLOAT128)
     # complex.h C23 _Complex _Float128 entrypoints
     libc.src.complex.crealf128
     libc.src.complex.cimagf128
+    libc.src.complex.conjf128
 
     # math.h C23 _Float128 entrypoints
     libc.src.math.canonicalizef128
diff --git a/libc/config/linux/arm/entrypoints.txt b/libc/config/linux/arm/entrypoints.txt
index 31d81de06fb6b..babdf92bb5676 100644
--- a/libc/config/linux/arm/entrypoints.txt
+++ b/libc/config/linux/arm/entrypoints.txt
@@ -207,6 +207,9 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.complex.cimag
     libc.src.complex.cimagf
     libc.src.complex.cimagl
+    libc.src.complex.conj
+    libc.src.complex.conjf
+    libc.src.complex.conjl
     
     # fenv.h entrypoints
     libc.src.fenv.feclearexcept
diff --git a/libc/config/linux/riscv/entrypoints.txt b/libc/config/linux/riscv/entrypoints.txt
index 5a48baf104159..59a5a1168f5dd 100644
--- a/libc/config/linux/riscv/entrypoints.txt
+++ b/libc/config/linux/riscv/entrypoints.txt
@@ -363,6 +363,9 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.complex.cimag
     libc.src.complex.cimagf
     libc.src.complex.cimagl
+    libc.src.complex.conj
+    libc.src.complex.conjf
+    libc.src.complex.conjl
 
     # fenv.h entrypoints
     libc.src.fenv.feclearexcept
@@ -618,6 +621,7 @@ if(LIBC_TYPES_HAS_FLOAT128)
     # complex.h C23 _Complex _Float128 entrypoints
     libc.src.complex.crealf128
     libc.src.complex.cimagf128
+    libc.src.complex.conjf128
     
     # math.h C23 _Float128 entrypoints
     libc.src.math.canonicalizef128
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index 1bedc25a9d029..21dd7e9a1d9da 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -365,6 +365,9 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.complex.cimag
     libc.src.complex.cimagf
     libc.src.complex.cimagl
+    libc.src.complex.conj
+    libc.src.complex.conjf
+    libc.src.complex.conjl
     
     # fenv.h entrypoints
     libc.src.fenv.feclearexcept
@@ -621,6 +624,7 @@ if(LIBC_TYPES_HAS_FLOAT16)
     # complex.h C23 _Complex _Float16 entrypoints
     libc.src.complex.crealf16
     libc.src.complex.cimagf16
+    libc.src.complex.conjf16
 
     # math.h C23 _Float16 entrypoints
     libc.src.math.canonicalizef16
@@ -730,6 +734,7 @@ if(LIBC_TYPES_HAS_FLOAT128)
     # complex.h C23 _Complex _Float128 entrypoints
     # libc.src.complex.crealf128
     # libc.src.complex.cimagf128
+    # libc.src.complex.conjf128
     
     # math.h C23 _Float128 entrypoints
     libc.src.math.canonicalizef128
diff --git a/libc/docs/headers/complex.rst b/libc/docs/headers/complex.rst
index 2e81aba97b0ef..b6a340543fad1 100644
--- a/libc/docs/headers/complex.rst
+++ b/libc/docs/headers/complex.rst
@@ -57,7 +57,7 @@ Functions
 +-----------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
 | cimag     | |check|          | |check|         | |check|                | |check|              | |check|                | 7.3.9.2                | N/A                        |
 +-----------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
-| conj      |                  |                 |                        |                      |                        | 7.3.9.4                | N/A                        |
+| conj      | |check|          | |check|         | |check|                | |check|              | |check|                | 7.3.9.4                | N/A                        |
 +-----------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
 | cproj     |                  |                 |                        |                      |                        | 7.3.9.5                | N/A                        |
 +-----------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
diff --git a/libc/src/__support/complex_type.h b/libc/src/__support/complex_type.h
index d6b5eec8fd6b2..4c861b05bc752 100644
--- a/libc/src/__support/complex_type.h
+++ b/libc/src/__support/complex_type.h
@@ -10,11 +10,70 @@
 #define LLVM_LIBC_SRC___SUPPORT_COMPLEX_TYPE_H
 
 #include "src/__support/macros/config.h"
+#include "src/__support/macros/properties/complex_types.h"
+#include "src/__support/macros/properties/types.h"
 
 namespace LIBC_NAMESPACE_DECL {
 template <typename T> struct Complex {
   T real;
   T imag;
 };
+
+template <typename T> struct make_complex;
+
+template <> struct make_complex<float> {
+  using type = _Complex float;
+};
+template <> struct make_complex<double> {
+  using type = _Complex double;
+};
+template <> struct make_complex<long double> {
+  using type = _Complex long double;
+};
+
+#if defined(LIBC_TYPES_HAS_CFLOAT16)
+template <> struct make_complex<float16> {
+  using type = cfloat16;
+};
+#endif
+#if defined(LIBC_TYPES_HAS_CFLOAT128)
+template <> struct make_complex<float128> {
+  using type = cfloat128;
+};
+#endif
+
+template <typename T> using make_complex_t = typename make_complex<T>::type;
+
+template <typename T> struct make_real;
+
+template <> struct make_real<_Complex float> {
+  using type = float;
+};
+template <> struct make_real<_Complex double> {
+  using type = double;
+};
+template <> struct make_real<_Complex long double> {
+  using type = long double;
+};
+
+#if defined(LIBC_TYPES_HAS_CFLOAT16)
+template <> struct make_real<cfloat16> {
+  using type = float16;
+};
+#endif
+#if defined(LIBC_TYPES_HAS_CFLOAT128)
+template <> struct make_real<cfloat128> {
+  using type = float128;
+};
+#endif
+
+template <typename T> using make_real_t = typename make_real<T>::type;
+
+template <typename T> LIBC_INLINE constexpr T conjugate(T c) {
+  Complex<make_real_t<T>> c_c = cpp::bit_cast<Complex<make_real_t<T>>>(c);
+  c_c.imag = -c_c.imag;
+  return cpp::bit_cast<T>(c_c);
+}
+
 } // namespace LIBC_NAMESPACE_DECL
 #endif // LLVM_LIBC_SRC___SUPPORT_COMPLEX_TYPE_H
diff --git a/libc/src/complex/CMakeLists.txt b/libc/src/complex/CMakeLists.txt
index 289cce5455af7..7306e2fe925e3 100644
--- a/libc/src/complex/CMakeLists.txt
+++ b/libc/src/complex/CMakeLists.txt
@@ -24,3 +24,9 @@ add_complex_entrypoint_object(cimagf)
 add_complex_entrypoint_object(cimagl)
 add_complex_entrypoint_object(cimagf16)
 add_complex_entrypoint_object(cimagf128)
+
+add_complex_entrypoint_object(conj)
+add_complex_entrypoint_object(conjf)
+add_complex_entrypoint_object(conjl)
+add_complex_entrypoint_object(conjf16)
+add_complex_entrypoint_object(conjf128)
diff --git a/libc/src/complex/conj.h b/libc/src/complex/conj.h
new file mode 100644
index 0000000000000..2ff82d2758620
--- /dev/null
+++ b/libc/src/complex/conj.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for conj --------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_COMPLEX_CONJ_H
+#define LLVM_LIBC_SRC_COMPLEX_CONJ_H
+
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+_Complex double conj(_Complex double x);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_COMPLEX_CONJ_H
diff --git a/libc/src/complex/conjf.h b/libc/src/complex/conjf.h
new file mode 100644
index 0000000000000..6b3bd612e5bf7
--- /dev/null
+++ b/libc/src/complex/conjf.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for conjf -------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_COMPLEX_CONJF_H
+#define LLVM_LIBC_SRC_COMPLEX_CONJF_H
+
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+_Complex float conjf(_Complex float x);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_COMPLEX_CONJF_H
diff --git a/libc/src/complex/conjf128.h b/libc/src/complex/conjf128.h
new file mode 100644
index 0000000000000..587c979d315ef
--- /dev/null
+++ b/libc/src/complex/conjf128.h
@@ -0,0 +1,27 @@
+//===-- Implementation header for conjf128 ----------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/__support/macros/properties/complex_types.h"
+#include "src/__support/macros/properties/types.h"
+
+#if defined(LIBC_TYPES_HAS_CFLOAT128)
+
+#ifndef LLVM_LIBC_SRC_COMPLEX_CONJF128_H
+#define LLVM_LIBC_SRC_COMPLEX_CONJF128_H
+
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+cfloat128 conjf128(cfloat128 x);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_COMPLEX_CONJF128_H
+
+#endif // LIBC_TYPES_HAS_CFLOAT128
diff --git a/libc/src/complex/conjf16.h b/libc/src/complex/conjf16.h
new file mode 100644
index 0000000000000..b15c5b3f61f4a
--- /dev/null
+++ b/libc/src/complex/conjf16.h
@@ -0,0 +1,27 @@
+//===-- Implementation header for conjf16 -----------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/__support/macros/properties/complex_types.h"
+#include "src/__support/macros/properties/types.h"
+
+#if defined(LIBC_TYPES_HAS_CFLOAT16)
+
+#ifndef LLVM_LIBC_SRC_COMPLEX_CONJF16_H
+#define LLVM_LIBC_SRC_COMPLEX_CONJF16_H
+
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+cfloat16 conjf16(cfloat16 x);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_COMPLEX_CONJF16_H
+
+#endif // LIBC_TYPES_HAS_CFLOAT16
diff --git a/libc/src/complex/conjl.h b/libc/src/complex/conjl.h
new file mode 100644
index 0000000000000..aec640f9433ac
--- /dev/null
+++ b/libc/src/complex/conjl.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for conjl -------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_COMPLEX_CONJL_H
+#define LLVM_LIBC_SRC_COMPLEX_CONJL_H
+
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+_Complex long double conjl(_Complex long double x);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_COMPLEX_CONJL_H
diff --git a/libc/src/complex/generic/CMakeLists.txt b/libc/src/complex/generic/CMakeLists.txt
index a3da781c60237..cc14f89122edd 100644
--- a/libc/src/complex/generic/CMakeLists.txt
+++ b/libc/src/complex/generic/CMakeLists.txt
@@ -1,3 +1,72 @@
+add_entrypoint_object(
+  conj
+  SRCS
+    conj.cpp
+  HDRS
+    ../conj.h
+  COMPILE_OPTIONS
+    ${libc_opt_high_flag}
+  DEPENDS
+    libc.src.__support.CPP.bit
+    libc.src.__support.complex_type
+)
+
+add_entrypoint_object(
+  conjf
+  SRCS
+    conjf.cpp
+  HDRS
+    ../conjf.h
+  COMPILE_OPTIONS
+    ${libc_opt_high_flag}
+  DEPENDS
+    libc.src.__support.CPP.bit
+    libc.src.__support.complex_type
+)
+
+add_entrypoint_object(
+  conjl
+  SRCS
+    conjl.cpp
+  HDRS
+    ../conjl.h
+  COMPILE_OPTIONS
+    ${libc_opt_high_flag}
+  DEPENDS
+    libc.src.__support.CPP.bit
+    libc.src.__support.complex_type
+)
+
+add_entrypoint_object(
+  conjf16
+  SRCS
+    conjf16.cpp
+  HDRS
+    ../conjf16.h
+  COMPILE_OPTIONS
+    ${libc_opt_high_flag}
+  DEPENDS
+    libc.src.__support.CPP.bit
+    libc.src.__support.complex_type
+    libc.src.__support.macros.properties.types
+    libc.src.__support.macros.properties.complex_types
+)
+
+add_entrypoint_object(
+  conjf128
+  SRCS
+    conjf128.cpp
+  HDRS
+    ../conjf128.h
+  COMPILE_OPTIONS
+    ${libc_opt_high_flag}
+  DEPENDS
+    libc.src.__support.CPP.bit
+    libc.src.__support.complex_type
+    libc.src.__support.macros.properties.types
+    libc.src.__support.macros.properties.complex_types
+)
+
 add_entrypoint_object(
   creal
   SRCS
diff --git a/libc/src/complex/generic/conj.cpp b/libc/src/complex/generic/conj.cpp
new file mode 100644
index 0000000000000..1a93bc25dc3c4
--- /dev/null
+++ b/libc/src/complex/generic/conj.cpp
@@ -0,0 +1,20 @@
+//===-- Implementation of conj function -----------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/complex/conj.h"
+#include "src/__support/CPP/bit.h"
+#include "src/__support/common.h"
+#include "src/__support/complex_type.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(_Complex double, conj, (_Complex double x)) {
+  return conjugate<_Complex double>(x);
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/complex/generic/conjf.cpp b/libc/src/complex/generic/conjf.cpp
new file mode 100644
index 0000000000000..33cb34340a04e
--- /dev/null
+++ b/libc/src/complex/generic/conjf.cpp
@@ -0,0 +1,20 @@
+//===-- Implementation of conjf function ----------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/complex/conjf.h"
+#include "src/__support/CPP/bit.h"
+#include "src/__support/common.h"
+#include "src/__support/complex_type.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(_Complex float, conjf, (_Complex float x)) {
+  return conjugate<_Complex float>(x);
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/complex/generic/conjf128.cpp b/libc/src/complex/generic/conjf128.cpp
new file mode 100644
index 0000000000000..4e35b3d5a97b7
--- /dev/null
+++ b/libc/src/complex/generic/conjf128.cpp
@@ -0,0 +1,24 @@
+//===-- Implementation of conjf128 function -------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/complex/conjf128.h"
+#if defined(LIBC_TYPES_HAS_CFLOAT128)
+
+#include "src/__support/CPP/bit.h"
+#include "src/__support/common.h"
+#include "src/__support/complex_type.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(cfloat128, conjf128, (cfloat128 x)) {
+  return conjugate<cfloat128>(x);
+}
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LIBC_TYPES_HAS_CFLOAT128
diff --git a/libc/src/complex/generic/conjf16.cpp b/libc/src/complex/generic/conjf16.cpp
new file mode 100644
index 0000000000000..2564fe252027a
--- /dev/null
+++ b/libc/src/complex/generic/conjf16.cpp
@@ -0,0 +1,24 @@
+//===-- Implementation of conjf16 function --------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/complex/conjf16.h"
+#if defined(LIBC_TYPES_HAS_CFLOAT16)
+
+#include "src/__support/CPP/bit.h"
+#include "src/__support/common.h"
+#include "src/__support/complex_type.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(cfloat16, conjf16, (cfloat16 x)) {
+  return conjugate<cfloat16>(x);
+}
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LIBC_TYPES_HAS_CFLOAT16
diff --git a/libc/src/complex/generic/conjl.cpp b/libc/src/complex/generic/conjl.cpp
new file mode 100644
index 0000000000000..dc071ab1ec51b
--- /dev/null
+++ b/libc/src/complex/generic/conjl.cpp
@@ -0,0 +1,20 @@
+//===-- Implementation of conjl function ----------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/complex/conjl.h"
+#include "src/__support/CPP/bit.h"
+#include "src/__support/common.h"
+#include "src/__support/complex_type.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(_Complex long double, conjl, (_Complex long double x)) {
+  return conjugate<_Complex long double>(x);
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/test/src/complex/CImagTest.h b/libc/test/src/complex/CImagTest.h
index 6d2f935002669..408460d97dfc6 100644
--- a/libc/test/src/complex/CImagTest.h
+++ b/libc/test/src/complex/CImagTest.h
@@ -38,9 +38,14 @@ class CImagTest : public LIBC_NAMESPACE::testing::FEnvSafeTest {
                  neg_min_denormal);
     EXPECT_FP_EQ(func(CFPT(1241.112 + max_denormal * 1.0i)), max_denormal);
     EXPECT_FP_EQ(func(CFPT(121.121 + zero * 1.0i)), zero);
-    EXPECT_FP_EQ(func(CFPT(neg_zero + zero * 1.0i)), zero);
-    EXPECT_FP_EQ(func(CFPT(neg_zero + neg_zero * 1.0i)), neg_zero);
-    EXPECT_FP_EQ(func(CFPT(zero + neg_zero * 1.0i)), neg_zero);
+    EXPECT_FP_EQ(func(CFPT(0.0 + 0.0i)), 0.0);
+    EXPECT_FP_EQ(func(CFPT(-0.0 + 0.0i)), 0.0);
+    EXPECT_FP_EQ(func(CFPT(0.0 - 0.0i)), -0.0);
+    EXPECT_FP_EQ(func(CFPT(-0.0 - 0.0i)), -0.0);
+    EXPECT_FP_EQ(func(CFPT(0.0)), 0.0);
+    EXPECT_FP_EQ(func(CFPT(-0.0)), 0.0);
+    EXPECT_FP_EQ(func(CFPT(0.0i)), 0.0);
+    EXPECT_FP_EQ(func(CFPT(-0.0i)), -0.0);
   }
 
   void testRoundedNumbers(CImagFunc func) {
diff --git a/libc/test/src/complex/CMakeLists.txt b/libc/test/src/complex/CMakeLists.txt
index 8f49e6d79e179..0c668d9e1e8b9 100644
--- a/libc/test/src/complex/CMakeLists.txt
+++ b/libc/test/src/complex/CMakeLists.txt
@@ -1,5 +1,65 @@
 add_custom_target(libc-complex-unittests)
 
+add_libc_test(
+  conj_test
+  SUITE
+    libc-complex-unittests
+  SRCS
+    conj_test.cpp
+  DEPENDS
+    libc.src.complex.conj
+  LINK_LIBRARIES
+      LibcFPTestHelpers
+)
+
+add_libc_test(
+  conjf_test
+  SUITE
+    libc-complex-unittests
+  SRCS
+    conjf_test.cpp
+  DEPENDS
+    libc.src.complex.conjf
+  LINK_LIBRARIES
+    LibcFPTestHelpers
+)
+
+add_libc_test(
+  conjl_test
+  SUITE
+    libc-complex-unittests
+  SRCS
+    conjl_test.cpp
+  DEPENDS
+    libc.src.complex.conjl
+  LINK_LIBRARIES
+    LibcFPTestHelpers
+)
+
+add_libc_test(
+  conjf16_test
+  SUITE
+    libc-complex-unittests
+  SRCS
+    conjf16_test.cpp
+  DEPENDS
+    libc.src.complex.conjf16
+  LINK_LIBRARIES
+    LibcFPTestHelpers
+)
+
+add_libc_test(
+  conjf128_test
+  SUITE
+    libc-complex-unittests
+  SRCS
+    conjf128_test.cpp
+  DEPENDS
+    libc.src.complex.conjf128
+  LINK_LIBRARIES
+    LibcFPTestHelpers
+)
+
 add_libc_test(
   creal_test
   SUITE
diff --git a/libc/test/src/complex/CRealTest.h b/libc/test/src/complex/CRealTest.h
index a25555b506e22..80eafc9975f4c 100644
--- a/libc/test/src/complex/CRealTest.h
+++ b/libc/test/src/complex/CRealTest.h
@@ -37,8 +37,14 @@ class CRealTest : public LIBC_NAMESPACE::testing::FEnvSafeTest {
     EXPECT_FP_EQ(func(CFPT(neg_min_denormal + 781.134i)), neg_min_denormal);
     EXPECT_FP_EQ(func(CFPT(max_denormal + 1241.112i)), max_denormal);
     EXPECT_FP_EQ(func(CFPT(zero + 121.121i)), zero);
-    EXPECT_FP_EQ(func(CFPT(neg_zero + neg_zero * 1.0i)), neg_zero);
-    EXPECT_FP_EQ(func(CFPT(neg_zero + zero * 1.0i)), zero);
+    EXPECT_FP_EQ(func(CFPT(0.0 + 0.0i)), 0.0);
+    EXPECT_FP_EQ(func(CFPT(-0.0 + 0.0i)), 0.0);
+    EXPECT_FP_EQ(func(CFPT(0.0 - 0.0i)), 0.0);
+    EXPECT_FP_EQ(func(CFPT(-0.0 - 0.0i)), -0.0);
+    EXPECT_FP_EQ(func(CFPT(0.0)), 0.0);
+    EXPECT_FP_EQ(func(CFPT(-0.0)), -0.0);
+    EXPECT_FP_EQ(func(CFPT(0.0i)), 0.0);
+    EXPECT_FP_EQ(func(CFPT(-0.0i)), -0.0);
   }
 
   void testRoundedNumbers(CRealFunc func) {
diff --git a/libc/test/src/complex/ConjTest.h b/libc/test/src/complex/ConjTest.h
new file mode 100644
index 0000000000000..da4fb4fd137c8
--- /dev/null
+++ b/libc/test/src/complex/ConjTest.h
@@ -0,0 +1,131 @@
+//===-- Utility class to test different flavors of conj ---------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_TEST_SRC_COMPLEX_CONJTEST_H
+#define LLVM_LIBC_TEST_SRC_COMPLEX_CONJTEST_H
+
+#include "test/UnitTest/FEnvSafeTest.h"
+#include "test/UnitTest/FPMatcher.h"
+#include "test/UnitTest/Test.h"
+
+#include "hdr/math_macros.h"
+
+template <typename CFPT, typename FPT>
+class ConjTest : public LIBC_NAMESPACE::testing::FEnvSafeTest {
+
+  DECLARE_SPECIAL_CONSTANTS(FPT)
+
+public:
+  typedef CFPT (*ConjFunc)(CFPT);
+
+  void testSpecialNumbers(ConjFunc func) {
+    EXPECT_CFP_EQ(func(CFPT(aNaN + 67.123i)), CFPT(aNaN - 67.123i));
+    EXPECT_CFP_EQ(func(CFPT(neg_aNaN + 78.319i)), CFPT(neg_aNaN - 78.319i));
+    EXPECT_CFP_EQ(func(CFPT(sNaN + 7813.131i)), CFPT(sNaN - 7813.131i));
+    EXPECT_CFP_EQ(func(CFPT(neg_sNaN + 7824.152i)), CFPT(neg_sNaN - 7824.152i));
+    EXPECT_CFP_EQ(func(CFPT(inf + 9024.2442i)), CFPT(inf - 9024.2442i));
+    EXPECT_CFP_EQ(func(CFPT(neg_inf + 8923.124i)), CFPT(neg_inf - 8923.124i));
+    EXPECT_CFP_EQ(func(CFPT(min_normal + 782.124i)),
+                  CFPT(min_normal - 782.124i));
+    EXPECT_CFP_EQ(func(CFPT(max_normal + 2141.2352i)),
+                  CFPT(max_normal - 2141.2352i));
+    EXPECT_CFP_EQ(func(CFPT(neg_max_normal + 341.134i)),
+                  CFPT(neg_max_normal - 341.134i));
+    EXPECT_CFP_EQ(func(CFPT(min_denormal + 781.142i)),
+                  CFPT(min_denormal - 781.142i));
+    EXPECT_CFP_EQ(func(CFPT(neg_min_denormal + 781.134i)),
+                  CFPT(neg_min_denormal - 781.134i));
+    EXPECT_CFP_EQ(func(CFPT(max_denormal + 1241.112i)),
+                  CFPT(max_denormal - 1241.112i));
+    EXPECT_CFP_EQ(func(CFPT(zero + 121.121i)), CFPT(zero - 121.121i));
+    EXPECT_CFP_EQ(func(CFPT(67.123 + aNaN * 1.0i)), CFPT(67.123 - aNaN * 1.0i));
+    EXPECT_CFP_EQ(func(CFPT(78.319 + neg_aNaN * 1.0i)),
+                  CFPT(78.319 - neg_aNaN * 1.0i));
+    EXPECT_CFP_EQ(func(CFPT(7813.131 + sNaN * 1.0i)),
+                  CFPT(7813.131 - sNaN * 1.0i));
+    EXPECT_CFP_EQ(func(CFPT(7824.152 + neg_sNaN * 1.0i)),
+                  CFPT(7824.152 - neg_sNaN * 1.0i));
+    EXPECT_CFP_EQ(func(CFPT(9024.2442 + inf * 1.0i)),
+                  CFPT(9024.2442 - inf * 1.0i));
+    EXPECT_CFP_EQ(func(CFPT(8923.124 + neg_inf * 1.0i)),
+                  CFPT(8923.124 - neg_inf * 1.0i));
+    EXPECT_CFP_EQ(func(CFPT(782.124 + min_normal * 1.0i)),
+                  CFPT(782.124 - min_normal * 1.0i));
+    EXPECT_CFP_EQ(func(CFPT(2141.2352 + max_normal * 1.0i)),
+                  CFPT(2141.2352 - max_normal * 1.0i));
+    EXPECT_CFP_EQ(func(CFPT(341.134 + neg_max_normal * 1.0i)),
+                  CFPT(341.134 - neg_max_normal * 1.0i));
+    EXPECT_CFP_EQ(func(CFPT(781.142 + min_denormal * 1.0i)),
+                  CFPT(781.142 - min_denormal * 1.0i));
+    EXPECT_CFP_EQ(func(CFPT(781.134 + neg_min_denormal * 1.0i)),
+                  CFPT(781.134 - neg_min_denormal * 1.0i));
+    EXPECT_CFP_EQ(func(CFPT(1241.112 + max_denormal * 1.0i)),
+                  CFPT(1241.112 - max_denormal * 1.0i));
+    EXPECT_CFP_EQ(func(CFPT(121.121 + zero * 1.0i)),
+                  CFPT(121.121 - zero * 1.0i));
+    EXPECT_CFP_EQ(func(CFPT(0.0 - 0.0i)), CFPT(0.0 + 0.0i));
+    EXPECT_CFP_EQ(func(CFPT(0.0 + 0.0i)), CFPT(0.0 - 0.0i));
+    // This test passes because the conjugate of -0.0 - 0.0i is CMPLX(-0.0, 0.0)
+    // which cannot be represented as -0.0 + 0.0i because -0.0 + 0.0i is
+    // actually CMPLX(-0.0, 0.0) + CMPLX(0.0, 0.0) = 0.0 + 0.0i so to represent
+    // CMPLX(-0.0, 0.0), we use -0.0
+    EXPECT_CFP_EQ(func(CFPT(-0.0 - 0.0i)), CFPT(-0.0));
+    // This test passes because -0.0 + 0.0i is actually
+    // CMPLX(-0.0, 0.0) + CMPLX(0.0, 0.0) = CMPLX(-0.0 + 0.0, 0.0) = 0.0 + 0.0i
+    EXPECT_CFP_EQ(func(CFPT(-0.0 + 0.0i)), CFPT(0.0 - 0.0i));
+    EXPECT_CFP_EQ(func(CFPT(0.0)), CFPT(0.0 - 0.0i));
+    EXPECT_CFP_EQ(func(CFPT(-0.0)), CFPT(-0.0 - 0.0i));
+    EXPECT_CFP_EQ(func(CFPT(0.0i)), CFPT(0.0 - 0.0i));
+    EXPECT_CFP_EQ(func(CFPT(-0.0i)), CFPT(-0.0));
+  }
+
+  void testRoundedNumbers(ConjFunc func) {
+    EXPECT_CFP_EQ(func((CFPT)(4523.1413 + 12413.1414i)),
+                  CFPT(4523.1413 - 12413.1414i));
+    EXPECT_CFP_EQ(func((CFPT)(-4523.1413 + 12413.1414i)),
+                  CFPT(-4523.1413 - 12413.1414i));
+    EXPECT_CFP_EQ(func((CFPT)(4523.1413 - 12413.1414i)),
+                  CFPT(4523.1413 + 12413.1414i));
+    EXPECT_CFP_EQ(func((CFPT)(-4523.1413 - 12413.1414i)),
+                  CFPT(-4523.1413 + 12413.1414i));
+
+    EXPECT_CFP_EQ(func((CFPT)(3210.5678 + 9876.5432i)),
+                  CFPT(3210.5678 - 9876.5432i));
+    EXPECT_CFP_EQ(func((CFPT)(-3210.5678 + 9876.5432i)),
+                  CFPT(-3210.5678 - 9876.5432i));
+    EXPECT_CFP_EQ(func((CFPT)(3210.5678 - 9876.5432i)),
+                  CFPT(3210.5678 + 9876.5432i));
+    EXPECT_CFP_EQ(func((CFPT)(-3210.5678 - 9876.5432i)),
+                  CFPT(-3210.5678 + 9876.5432i));
+
+    EXPECT_CFP_EQ(func((CFPT)(1234.4321 + 4321.1234i)),
+                  CFPT(1234.4321 - 4321.1234i));
+    EXPECT_CFP_EQ(func((CFPT)(-1234.4321 + 4321.1234i)),
+                  CFPT(-1234.4321 - 4321.1234i));
+    EXPECT_CFP_EQ(func((CFPT)(1234.4321 - 4321.1234i)),
+                  CFPT(1234.4321 + 4321.1234i));
+    EXPECT_CFP_EQ(func((CFPT)(-1234.4321 - 4321.1234i)),
+                  CFPT(-1234.4321 + 4321.1234i));
+
+    EXPECT_CFP_EQ(func((CFPT)(6789.1234 + 8765.6789i)),
+                  CFPT(6789.1234 - 8765.6789i));
+    EXPECT_CFP_EQ(func((CFPT)(-6789.1234 + 8765.6789i)),
+                  CFPT(-6789.1234 - 8765.6789i));
+    EXPECT_CFP_EQ(func((CFPT)(6789.1234 - 8765.6789i)),
+                  CFPT(6789.1234 + 8765.6789i));
+    EXPECT_CFP_EQ(func((CFPT)(-6789.1234 - 8765.6789i)),
+                  CFPT(-6789.1234 + 8765.6789i));
+  }
+};
+
+#define LIST_CONJ_TESTS(U, T, func)                                            \
+  using LlvmLibcConjTest = ConjTest<U, T>;                                     \
+  TEST_F(LlvmLibcConjTest, SpecialNumbers) { testSpecialNumbers(&func); }      \
+  TEST_F(LlvmLibcConjTest, RoundedNumbers) { testRoundedNumbers(&func); }
+
+#endif // LLVM_LIBC_TEST_SRC_COMPLEX_CONJTEST_H
diff --git a/libc/test/src/complex/conj_test.cpp b/libc/test/src/complex/conj_test.cpp
new file mode 100644
index 0000000000000..97445fa065088
--- /dev/null
+++ b/libc/test/src/complex/conj_test.cpp
@@ -0,0 +1,13 @@
+//===-- Unittests for conj ------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "ConjTest.h"
+
+#include "src/complex/conj.h"
+
+LIST_CONJ_TESTS(_Complex double, double, LIBC_NAMESPACE::conj)
diff --git a/libc/test/src/complex/conjf128_test.cpp b/libc/test/src/complex/conjf128_test.cpp
new file mode 100644
index 0000000000000..a1feb9ff31fdc
--- /dev/null
+++ b/libc/test/src/complex/conjf128_test.cpp
@@ -0,0 +1,17 @@
+//===-- Unittests for conjf128 --------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "ConjTest.h"
+
+#include "src/complex/conjf128.h"
+
+#if defined(LIBC_TYPES_HAS_CFLOAT128)
+
+LIST_CONJ_TESTS(cfloat128, float128, LIBC_NAMESPACE::conjf128)
+
+#endif // LIBC_TYPES_HAS_CFLOAT128
diff --git a/libc/test/src/complex/conjf16_test.cpp b/libc/test/src/complex/conjf16_test.cpp
new file mode 100644
index 0000000000000..0de9f448e8681
--- /dev/null
+++ b/libc/test/src/complex/conjf16_test.cpp
@@ -0,0 +1,17 @@
+//===-- Unittests for conjf16 ---------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "ConjTest.h"
+
+#include "src/complex/conjf16.h"
+
+#if defined(LIBC_TYPES_HAS_CFLOAT16)
+
+LIST_CONJ_TESTS(cfloat16, float16, LIBC_NAMESPACE::conjf16)
+
+#endif // LIBC_TYPES_HAS_CFLOAT16
diff --git a/libc/test/src/complex/conjf_test.cpp b/libc/test/src/complex/conjf_test.cpp
new file mode 100644
index 0000000000000..34b00b37996c3
--- /dev/null
+++ b/libc/test/src/complex/conjf_test.cpp
@@ -0,0 +1,13 @@
+//===-- Unittests for conjf -----------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "ConjTest.h"
+
+#include "src/complex/conjf.h"
+
+LIST_CONJ_TESTS(_Complex float, float, LIBC_NAMESPACE::conjf)
diff --git a/libc/test/src/complex/conjl_test.cpp b/libc/test/src/complex/conjl_test.cpp
new file mode 100644
index 0000000000000..ec299f9631547
--- /dev/null
+++ b/libc/test/src/complex/conjl_test.cpp
@@ -0,0 +1,13 @@
+//===-- Unittests for conjl -----------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "ConjTest.h"
+
+#include "src/complex/conjl.h"
+
+LIST_CONJ_TESTS(_Complex long double, long double, LIBC_NAMESPACE::conjl)