diff --git a/openmp/runtime/src/kmp.h b/openmp/runtime/src/kmp.h
index 9b8c6102dbee2..3d34513491154 100644
--- a/openmp/runtime/src/kmp.h
+++ b/openmp/runtime/src/kmp.h
@@ -1354,6 +1354,10 @@ extern kmp_uint64 __kmp_now_nsec();
 /* TODO: tune for KMP_OS_OPENBSD */
 #define KMP_INIT_WAIT 1024U /* initial number of spin-tests   */
 #define KMP_NEXT_WAIT 512U /* susequent number of spin-tests */
+#elif KMP_OS_HAIKU
+/* TODO: tune for KMP_OS_HAIKU */
+#define KMP_INIT_WAIT 1024U /* initial number of spin-tests   */
+#define KMP_NEXT_WAIT 512U /* susequent number of spin-tests */
 #elif KMP_OS_HURD
 /* TODO: tune for KMP_OS_HURD */
 #define KMP_INIT_WAIT 1024U /* initial number of spin-tests   */
diff --git a/openmp/runtime/src/kmp_ftn_entry.h b/openmp/runtime/src/kmp_ftn_entry.h
index 9bd3ac973b352..9c8be5f953d35 100644
--- a/openmp/runtime/src/kmp_ftn_entry.h
+++ b/openmp/runtime/src/kmp_ftn_entry.h
@@ -582,7 +582,8 @@ int FTN_STDCALL KMP_EXPAND_NAME(FTN_GET_THREAD_NUM)(void) {
   int gtid;
 
 #if KMP_OS_DARWIN || KMP_OS_DRAGONFLY || KMP_OS_FREEBSD || KMP_OS_NETBSD ||    \
-    KMP_OS_OPENBSD || KMP_OS_HURD || KMP_OS_SOLARIS || KMP_OS_AIX
+    KMP_OS_OPENBSD || KMP_OS_HAIKU || KMP_OS_HURD || KMP_OS_SOLARIS ||         \
+    KMP_OS_AIX
   gtid = __kmp_entry_gtid();
 #elif KMP_OS_WINDOWS
   if (!__kmp_init_parallel ||
diff --git a/openmp/runtime/src/kmp_platform.h b/openmp/runtime/src/kmp_platform.h
index 2f47efd3e85ff..9ed14159376cc 100644
--- a/openmp/runtime/src/kmp_platform.h
+++ b/openmp/runtime/src/kmp_platform.h
@@ -22,6 +22,7 @@
 #define KMP_OS_OPENBSD 0
 #define KMP_OS_DARWIN 0
 #define KMP_OS_WINDOWS 0
+#define KMP_OS_HAIKU 0
 #define KMP_OS_HURD 0
 #define KMP_OS_SOLARIS 0
 #define KMP_OS_WASI 0
@@ -73,6 +74,11 @@
 #define KMP_OS_OPENBSD 1
 #endif
 
+#if (defined __HAIKU__)
+#undef KMP_OS_HAIKU
+#define KMP_OS_HAIKU 1
+#endif
+
 #if (defined __GNU__)
 #undef KMP_OS_HURD
 #define KMP_OS_HURD 1
@@ -94,14 +100,14 @@
 #endif
 
 #if (1 != KMP_OS_LINUX + KMP_OS_DRAGONFLY + KMP_OS_FREEBSD + KMP_OS_NETBSD +   \
-              KMP_OS_OPENBSD + KMP_OS_DARWIN + KMP_OS_WINDOWS + KMP_OS_HURD +  \
-              KMP_OS_SOLARIS + KMP_OS_WASI + KMP_OS_AIX)
+              KMP_OS_OPENBSD + KMP_OS_DARWIN + KMP_OS_WINDOWS + KMP_OS_HAIKU + \
+              KMP_OS_HURD + KMP_OS_SOLARIS + KMP_OS_WASI + KMP_OS_AIX)
 #error Unknown OS
 #endif
 
 #if KMP_OS_LINUX || KMP_OS_DRAGONFLY || KMP_OS_FREEBSD || KMP_OS_NETBSD ||     \
-    KMP_OS_OPENBSD || KMP_OS_DARWIN || KMP_OS_HURD || KMP_OS_SOLARIS ||        \
-    KMP_OS_WASI || KMP_OS_AIX
+    KMP_OS_OPENBSD || KMP_OS_DARWIN || KMP_OS_HAIKU || KMP_OS_HURD ||          \
+    KMP_OS_SOLARIS || KMP_OS_WASI || KMP_OS_AIX
 #undef KMP_OS_UNIX
 #define KMP_OS_UNIX 1
 #endif
diff --git a/openmp/runtime/src/kmp_runtime.cpp b/openmp/runtime/src/kmp_runtime.cpp
index 3e5d671cb7a48..64548b1397c34 100644
--- a/openmp/runtime/src/kmp_runtime.cpp
+++ b/openmp/runtime/src/kmp_runtime.cpp
@@ -8949,8 +8949,8 @@ __kmp_determine_reduction_method(
     KMP_ARCH_VE || KMP_ARCH_S390X || KMP_ARCH_WASM
 
 #if KMP_OS_LINUX || KMP_OS_DRAGONFLY || KMP_OS_FREEBSD || KMP_OS_NETBSD ||     \
-    KMP_OS_OPENBSD || KMP_OS_WINDOWS || KMP_OS_DARWIN || KMP_OS_HURD ||        \
-    KMP_OS_SOLARIS || KMP_OS_WASI || KMP_OS_AIX
+    KMP_OS_OPENBSD || KMP_OS_WINDOWS || KMP_OS_DARWIN || KMP_OS_HAIKU ||       \
+    KMP_OS_HURD || KMP_OS_SOLARIS || KMP_OS_WASI || KMP_OS_AIX
 
     int teamsize_cutoff = 4;
 
@@ -8974,15 +8974,15 @@ __kmp_determine_reduction_method(
 #else
 #error "Unknown or unsupported OS"
 #endif // KMP_OS_LINUX || KMP_OS_DRAGONFLY || KMP_OS_FREEBSD || KMP_OS_NETBSD ||
-       // KMP_OS_OPENBSD || KMP_OS_WINDOWS || KMP_OS_DARWIN || KMP_OS_HURD ||
-       // KMP_OS_SOLARIS || KMP_OS_WASI || KMP_OS_AIX
+       // KMP_OS_OPENBSD || KMP_OS_WINDOWS || KMP_OS_DARWIN || KMP_OS_HAIKU ||
+       // KMP_OS_HURD || KMP_OS_SOLARIS || KMP_OS_WASI || KMP_OS_AIX
 
 #elif KMP_ARCH_X86 || KMP_ARCH_ARM || KMP_ARCH_AARCH || KMP_ARCH_MIPS ||       \
     KMP_ARCH_WASM || KMP_ARCH_PPC || KMP_ARCH_AARCH64_32
 
 #if KMP_OS_LINUX || KMP_OS_DRAGONFLY || KMP_OS_FREEBSD || KMP_OS_NETBSD ||     \
-    KMP_OS_OPENBSD || KMP_OS_WINDOWS || KMP_OS_HURD || KMP_OS_SOLARIS ||       \
-    KMP_OS_WASI || KMP_OS_AIX
+    KMP_OS_OPENBSD || KMP_OS_WINDOWS || KMP_OS_HAIKU || KMP_OS_HURD ||         \
+    KMP_OS_SOLARIS || KMP_OS_WASI || KMP_OS_AIX
 
     // basic tuning
 
diff --git a/openmp/runtime/src/kmp_wrapper_getpid.h b/openmp/runtime/src/kmp_wrapper_getpid.h
index d31c6e80f75df..6b41dfcc20880 100644
--- a/openmp/runtime/src/kmp_wrapper_getpid.h
+++ b/openmp/runtime/src/kmp_wrapper_getpid.h
@@ -17,7 +17,7 @@
 
 // On Unix-like systems (Linux* OS and OS X*) getpid() is declared in standard
 // headers.
-#if !defined(KMP_OS_AIX)
+#if !defined(KMP_OS_AIX) && !defined(KMP_OS_HAIKU)
 #include <sys/syscall.h>
 #endif
 #include <sys/types.h>
@@ -36,6 +36,9 @@
 #elif KMP_OS_AIX
 #include <pthread.h>
 #define __kmp_gettid() pthread_self()
+#elif KMP_OS_HAIKU
+#include <OS.h>
+#define __kmp_gettid() find_thread(NULL)
 #elif defined(SYS_gettid)
 // Hopefully other Unix systems define SYS_gettid syscall for getting os thread
 // id
diff --git a/openmp/runtime/src/z_Linux_util.cpp b/openmp/runtime/src/z_Linux_util.cpp
index bdb7a12cef5e9..0c89f2346750f 100644
--- a/openmp/runtime/src/z_Linux_util.cpp
+++ b/openmp/runtime/src/z_Linux_util.cpp
@@ -32,7 +32,7 @@
 #if KMP_OS_AIX
 #include <sys/ldr.h>
 #include <libperfstat.h>
-#else
+#elif !KMP_OS_HAIKU
 #include <sys/syscall.h>
 #endif
 #include <sys/time.h>
@@ -465,7 +465,7 @@ void __kmp_terminate_thread(int gtid) {
 static kmp_int32 __kmp_set_stack_info(int gtid, kmp_info_t *th) {
   int stack_data;
 #if KMP_OS_LINUX || KMP_OS_DRAGONFLY || KMP_OS_FREEBSD || KMP_OS_NETBSD ||     \
-    KMP_OS_HURD || KMP_OS_SOLARIS || KMP_OS_AIX
+    KMP_OS_HAIKU || KMP_OS_HURD || KMP_OS_SOLARIS || KMP_OS_AIX
   int status;
   size_t size = 0;
   void *addr = 0;
@@ -517,7 +517,7 @@ static kmp_int32 __kmp_set_stack_info(int gtid, kmp_info_t *th) {
     return TRUE;
   }
 #endif /* KMP_OS_LINUX || KMP_OS_DRAGONFLY || KMP_OS_FREEBSD || KMP_OS_NETBSD  \
-          || KMP_OS_HURD || KMP_OS_SOLARIS */
+          || KMP_OS_HAIKU || KMP_OS_HURD || KMP_OS_SOLARIS */
   /* Use incremental refinement starting from initial conservative estimate */
   TCW_PTR(th->th.th_info.ds.ds_stacksize, 0);
   TCW_PTR(th->th.th_info.ds.ds_stackbase, &stack_data);
@@ -532,7 +532,8 @@ static void *__kmp_launch_worker(void *thr) {
 #endif /* KMP_BLOCK_SIGNALS */
   void *exit_val;
 #if KMP_OS_LINUX || KMP_OS_DRAGONFLY || KMP_OS_FREEBSD || KMP_OS_NETBSD ||     \
-    KMP_OS_OPENBSD || KMP_OS_HURD || KMP_OS_SOLARIS || KMP_OS_AIX
+    KMP_OS_OPENBSD || KMP_OS_HAIKU || KMP_OS_HURD || KMP_OS_SOLARIS ||         \
+    KMP_OS_AIX
   void *volatile padding = 0;
 #endif
   int gtid;
@@ -581,7 +582,8 @@ static void *__kmp_launch_worker(void *thr) {
 #endif /* KMP_BLOCK_SIGNALS */
 
 #if KMP_OS_LINUX || KMP_OS_DRAGONFLY || KMP_OS_FREEBSD || KMP_OS_NETBSD ||     \
-    KMP_OS_OPENBSD || KMP_OS_HURD || KMP_OS_SOLARIS || KMP_OS_AIX
+    KMP_OS_OPENBSD || KMP_OS_HAIKU || KMP_OS_HURD || KMP_OS_SOLARIS ||         \
+    KMP_OS_AIX
   if (__kmp_stkoffset > 0 && gtid > 0) {
     padding = KMP_ALLOCA(gtid * __kmp_stkoffset);
     (void)padding;
@@ -1902,7 +1904,7 @@ static int __kmp_get_xproc(void) {
   __kmp_type_convert(sysconf(_SC_NPROCESSORS_CONF), &(r));
 
 #elif KMP_OS_DRAGONFLY || KMP_OS_FREEBSD || KMP_OS_NETBSD || KMP_OS_OPENBSD || \
-    KMP_OS_HURD || KMP_OS_SOLARIS || KMP_OS_WASI || KMP_OS_AIX
+    KMP_OS_HAIKU || KMP_OS_HURD || KMP_OS_SOLARIS || KMP_OS_WASI || KMP_OS_AIX
 
   __kmp_type_convert(sysconf(_SC_NPROCESSORS_ONLN), &(r));
 
@@ -2400,6 +2402,9 @@ int __kmp_is_address_mapped(void *addr) {
   }
   KMP_INTERNAL_FREE(loadQueryBuf);
 
+#elif KMP_OS_HAIKU
+
+  found = 1;
 #else
 
 #error "Unknown or unsupported OS"
@@ -2515,7 +2520,9 @@ int __kmp_get_load_balance(int max) {
   glb_running_threads = running_threads;
 
   return running_threads;
-}
+#elif KMP_OS_HAIKU
+
+int __kmp_get_load_balance(int max) { return -1; }
 
 #else // Linux* OS
 
diff --git a/openmp/runtime/test/lit.cfg b/openmp/runtime/test/lit.cfg
index 2a9ae05f97552..cfbd2c5d418b5 100644
--- a/openmp/runtime/test/lit.cfg
+++ b/openmp/runtime/test/lit.cfg
@@ -19,6 +19,9 @@ def prepend_dynamic_library_path(path):
     elif config.operating_system == 'Darwin':
         name = 'DYLD_LIBRARY_PATH'
         sep = ':'
+    elif config.operating_system == 'Haiku':
+        name = 'LIBRARY_PATH'
+        sep = ':'
     elif target_arch == 've':
         name = 'VE_LD_LIBRARY_PATH'
         sep = ':'
@@ -60,10 +63,11 @@ config.test_flags_use_compiler_omp_h = flags
 
 # extra libraries
 libs = ""
-if config.has_libm:
-    libs += " -lm"
-if config.has_libatomic:
-    libs += " -latomic"
+if config.operating_system != 'Haiku':
+    if config.has_libm:
+        libs += " -lm"
+    if config.has_libatomic:
+        libs += " -latomic"
 
 # Allow REQUIRES / UNSUPPORTED / XFAIL to work
 config.target_triple = [ ]
diff --git a/openmp/tools/multiplex/ompt-multiplex.h b/openmp/tools/multiplex/ompt-multiplex.h
index a73f2b375852d..4c17802a3769e 100644
--- a/openmp/tools/multiplex/ompt-multiplex.h
+++ b/openmp/tools/multiplex/ompt-multiplex.h
@@ -21,7 +21,9 @@
 #endif
 #include <dlfcn.h>
 #include <errno.h>
+#ifndef __HAIKU__
 #include <execinfo.h>
+#endif
 #include <inttypes.h>
 #include <omp-tools.h>
 #include <omp.h>