diff --git a/CHANGELOG.md b/CHANGELOG.md
index 00624db01f..9fdce66550 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -63,6 +63,8 @@ Unreleased changes template.
 * (gazelle) Providing multiple input requirements files to `gazelle_python_manifest` now works correctly.
 * (pypi) Handle trailing slashes in pip index URLs in environment variables,
   fixes [#2554](https://github.com/bazelbuild/rules_python/issues/2554).
+* (runfiles) Runfile manifest and repository mapping files are now interpreted
+  as UTF-8 on all platforms.
 
 {#v0-0-0-added}
 ### Added
diff --git a/examples/bzlmod/runfiles/runfiles_test.py b/examples/bzlmod/runfiles/runfiles_test.py
index e1ba14e569..7b7e87726a 100644
--- a/examples/bzlmod/runfiles/runfiles_test.py
+++ b/examples/bzlmod/runfiles/runfiles_test.py
@@ -27,36 +27,36 @@ def testCurrentRepository(self):
 
     def testRunfilesWithRepoMapping(self):
         data_path = runfiles.Create().Rlocation("example_bzlmod/runfiles/data/data.txt")
-        with open(data_path) as f:
+        with open(data_path, "rt", encoding="utf-8", newline="\n") as f:
             self.assertEqual(f.read().strip(), "Hello, example_bzlmod!")
 
     def testRunfileWithRlocationpath(self):
         data_rlocationpath = os.getenv("DATA_RLOCATIONPATH")
         data_path = runfiles.Create().Rlocation(data_rlocationpath)
-        with open(data_path) as f:
+        with open(data_path, "rt", encoding="utf-8", newline="\n") as f:
             self.assertEqual(f.read().strip(), "Hello, example_bzlmod!")
 
     def testRunfileInOtherModuleWithOurRepoMapping(self):
         data_path = runfiles.Create().Rlocation(
             "our_other_module/other_module/pkg/data/data.txt"
         )
-        with open(data_path) as f:
+        with open(data_path, "rt", encoding="utf-8", newline="\n") as f:
             self.assertEqual(f.read().strip(), "Hello, other_module!")
 
     def testRunfileInOtherModuleWithItsRepoMapping(self):
         data_path = lib.GetRunfilePathWithRepoMapping()
-        with open(data_path) as f:
+        with open(data_path, "rt", encoding="utf-8", newline="\n") as f:
             self.assertEqual(f.read().strip(), "Hello, other_module!")
 
     def testRunfileInOtherModuleWithCurrentRepository(self):
         data_path = lib.GetRunfilePathWithCurrentRepository()
-        with open(data_path) as f:
+        with open(data_path, "rt", encoding="utf-8", newline="\n") as f:
             self.assertEqual(f.read().strip(), "Hello, other_module!")
 
     def testRunfileInOtherModuleWithRlocationpath(self):
         data_rlocationpath = os.getenv("OTHER_MODULE_DATA_RLOCATIONPATH")
         data_path = runfiles.Create().Rlocation(data_rlocationpath)
-        with open(data_path) as f:
+        with open(data_path, "rt", encoding="utf-8", newline="\n") as f:
             self.assertEqual(f.read().strip(), "Hello, other_module!")
 
 
diff --git a/examples/bzlmod_build_file_generation/runfiles/runfiles_test.py b/examples/bzlmod_build_file_generation/runfiles/runfiles_test.py
index 5bfa5302ef..6ce4c2db37 100644
--- a/examples/bzlmod_build_file_generation/runfiles/runfiles_test.py
+++ b/examples/bzlmod_build_file_generation/runfiles/runfiles_test.py
@@ -29,36 +29,36 @@ def testRunfilesWithRepoMapping(self):
         data_path = runfiles.Create().Rlocation(
             "example_bzlmod_build_file_generation/runfiles/data/data.txt"
         )
-        with open(data_path) as f:
+        with open(data_path, "rt", encoding="utf-8", newline="\n") as f:
             self.assertEqual(f.read().strip(), "Hello, example_bzlmod!")
 
     def testRunfileWithRlocationpath(self):
         data_rlocationpath = os.getenv("DATA_RLOCATIONPATH")
         data_path = runfiles.Create().Rlocation(data_rlocationpath)
-        with open(data_path) as f:
+        with open(data_path, "rt", encoding="utf-8", newline="\n") as f:
             self.assertEqual(f.read().strip(), "Hello, example_bzlmod!")
 
     def testRunfileInOtherModuleWithOurRepoMapping(self):
         data_path = runfiles.Create().Rlocation(
             "our_other_module/other_module/pkg/data/data.txt"
         )
-        with open(data_path) as f:
+        with open(data_path, "rt", encoding="utf-8", newline="\n") as f:
             self.assertEqual(f.read().strip(), "Hello, other_module!")
 
     def testRunfileInOtherModuleWithItsRepoMapping(self):
         data_path = lib.GetRunfilePathWithRepoMapping()
-        with open(data_path) as f:
+        with open(data_path, "rt", encoding="utf-8", newline="\n") as f:
             self.assertEqual(f.read().strip(), "Hello, other_module!")
 
     def testRunfileInOtherModuleWithCurrentRepository(self):
         data_path = lib.GetRunfilePathWithCurrentRepository()
-        with open(data_path) as f:
+        with open(data_path, "rt", encoding="utf-8", newline="\n") as f:
             self.assertEqual(f.read().strip(), "Hello, other_module!")
 
     def testRunfileInOtherModuleWithRlocationpath(self):
         data_rlocationpath = os.getenv("OTHER_MODULE_DATA_RLOCATIONPATH")
         data_path = runfiles.Create().Rlocation(data_rlocationpath)
-        with open(data_path) as f:
+        with open(data_path, "rt", encoding="utf-8", newline="\n") as f:
             self.assertEqual(f.read().strip(), "Hello, other_module!")
 
 
diff --git a/python/runfiles/runfiles.py b/python/runfiles/runfiles.py
index ea816c64fd..3943be5646 100644
--- a/python/runfiles/runfiles.py
+++ b/python/runfiles/runfiles.py
@@ -56,7 +56,7 @@ def RlocationChecked(self, path: str) -> Optional[str]:
     def _LoadRunfiles(path: str) -> Dict[str, str]:
         """Loads the runfiles manifest."""
         result = {}
-        with open(path, "r") as f:
+        with open(path, "r", encoding="utf-8", newline="\n") as f:
             for line in f:
                 line = line.rstrip("\n")
                 if line.startswith(" "):
@@ -367,7 +367,7 @@ def _ParseRepoMapping(repo_mapping_path: Optional[str]) -> Dict[Tuple[str, str],
     if not repo_mapping_path:
         return {}
     try:
-        with open(repo_mapping_path, "r") as f:
+        with open(repo_mapping_path, "r", encoding="utf-8", newline="\n") as f:
             content = f.read()
     except FileNotFoundError:
         return {}
diff --git a/tests/runfiles/runfiles_test.py b/tests/runfiles/runfiles_test.py
index cf6a70a020..a3837ac842 100644
--- a/tests/runfiles/runfiles_test.py
+++ b/tests/runfiles/runfiles_test.py
@@ -552,7 +552,7 @@ def __init__(
     def __enter__(self) -> Any:
         tmpdir = os.environ.get("TEST_TMPDIR")
         self._path = os.path.join(tempfile.mkdtemp(dir=tmpdir), self._name)
-        with open(self._path, "wt") as f:
+        with open(self._path, "wt", encoding="utf-8", newline="\n") as f:
             f.writelines(l + "\n" for l in self._contents)
         return self