diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -10,6 +10,7 @@
     libc.src.string.strcat
     libc.src.string.strlen
     libc.src.string.memchr
+    libc.src.string.strchr
 )
 
 set(TARGET_LIBM_ENTRYPOINTS
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -28,6 +28,7 @@
     libc.src.string.strlen
     libc.src.string.strcmp
     libc.src.string.memchr
+    libc.src.string.strchr
 
     # sys/mman.h entrypoints
     libc.src.sys.mman.mmap
diff --git a/libc/src/string/CMakeLists.txt b/libc/src/string/CMakeLists.txt
--- a/libc/src/string/CMakeLists.txt
+++ b/libc/src/string/CMakeLists.txt
@@ -52,6 +52,15 @@
     memchr.h
 )
 
+add_entrypoint_object(
+  strchr
+  SRCS
+    strchr.cpp
+  HDRS
+    strchr.h
+  DEPENDS
+    .strlen
+)
 
 # Helper to define a function with multiple implementations
 # - Computes flags to satisfy required/rejected features and arch,
diff --git a/libc/src/string/strchr.h b/libc/src/string/strchr.h
new file mode 100644
--- /dev/null
+++ b/libc/src/string/strchr.h
@@ -0,0 +1,18 @@
+//===-- Implementation header for strchr ------------------------*- 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_STRING_STRCHR_H
+#define LLVM_LIBC_SRC_STRING_STRCHR_H
+
+namespace __llvm_libc {
+
+char *strchr(const char *src, int c);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_STRING_STRCHR_H
diff --git a/libc/src/string/strchr.cpp b/libc/src/string/strchr.cpp
new file mode 100644
--- /dev/null
+++ b/libc/src/string/strchr.cpp
@@ -0,0 +1,27 @@
+//===-- Implementation of strchr ------------------------------------------===//
+//
+// 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/string/strchr.h"
+#include "src/string/strlen.h"
+
+#include "src/__support/common.h"
+
+namespace __llvm_libc {
+
+// TODO: Look at performance benefits of comparing words.
+char *LLVM_LIBC_ENTRYPOINT(strchr)(const char *src, int c) {
+  char *str = const_cast<char *>(src);
+  if (!c)
+    return str + __llvm_libc::strlen(str);
+
+  for (; *str && *str != c; ++str)
+    ;
+  return *str == c ? str : nullptr;
+}
+
+} // namespace __llvm_libc
diff --git a/libc/test/src/string/CMakeLists.txt b/libc/test/src/string/CMakeLists.txt
--- a/libc/test/src/string/CMakeLists.txt
+++ b/libc/test/src/string/CMakeLists.txt
@@ -52,6 +52,16 @@
     libc.src.string.memchr
 )
 
+add_libc_unittest(
+  strchr_test
+  SUITE
+    libc_string_unittests
+  SRCS
+    strchr_test.cpp
+  DEPENDS
+    libc.src.string.strchr
+)
+
 # Tests all implementations that can run on the host.
 function(add_libc_multi_impl_test name)
   get_property(fq_implementations GLOBAL PROPERTY ${name}_implementations)
diff --git a/libc/test/src/string/strchr_test.cpp b/libc/test/src/string/strchr_test.cpp
new file mode 100644
--- /dev/null
+++ b/libc/test/src/string/strchr_test.cpp
@@ -0,0 +1,66 @@
+//===-- Unittests for strchr ----------------------------------------------===//
+//
+// 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/string/strchr.h"
+#include "utils/UnitTest/Test.h"
+
+TEST(StrChrTest, FindsFirstCharacter) {
+  // Should return original string since 'a' is the first character.
+  ASSERT_STREQ(__llvm_libc::strchr("abcde", 'a'), "abcde");
+}
+
+TEST(StrChrTest, FindsMiddleCharacter) {
+  // Should return characters after (and including) 'c'.
+  ASSERT_STREQ(__llvm_libc::strchr("abcde", 'c'), "cde");
+}
+
+TEST(StrChrTest, FindsLastCharacterThatIsNotNullTerminator) {
+  // Should return 'e' and null-terminator.
+  ASSERT_STREQ(__llvm_libc::strchr("abcde", 'e'), "e");
+}
+
+TEST(StrChrTest, FindsNullTerminator) {
+  // Should return null terminator.
+  ASSERT_STREQ(__llvm_libc::strchr("abcde", '\0'), "");
+}
+
+TEST(StrChrTest, CharacterNotWithinStringShouldReturnNullptr) {
+  // Since 'z' is not within the string, should return nullptr.
+  ASSERT_STREQ(__llvm_libc::strchr("123?", 'z'), nullptr);
+}
+
+TEST(StrChrTest, TheSourceShouldNotChange) {
+  const char *src = "abcde";
+  const char *src_copy = src;
+  // When the character is found, the source string should not change.
+  __llvm_libc::strchr(src, 'd');
+  ASSERT_STREQ(src, src_copy);
+  // Same case for when the character is not found.
+  __llvm_libc::strchr(src, 'z');
+  ASSERT_STREQ(src, src_copy);
+}
+
+TEST(StrChrTest, ShouldFindFirstOfDuplicates) {
+  // '1' is duplicated in the string, but it should find the first copy.
+  ASSERT_STREQ(__llvm_libc::strchr("abc1def1ghi", '1'), "1def1ghi");
+}
+
+TEST(StrChrTest, EmptyStringShouldOnlyMatchNullTerminator) {
+  // Null terminator should match.
+  ASSERT_STREQ(__llvm_libc::strchr("", '\0'), "");
+  // All other characters should not match.
+  ASSERT_STREQ(__llvm_libc::strchr("", 'Z'), nullptr);
+  ASSERT_STREQ(__llvm_libc::strchr("", '3'), nullptr);
+  ASSERT_STREQ(__llvm_libc::strchr("", '*'), nullptr);
+}
+
+TEST(StrChrTest, SingleRepeatedCharacterShouldReturnFirstInstance) {
+  const char *dups = "XXXXX";
+  // Should return original string since 'X' is the first character.
+  ASSERT_STREQ(__llvm_libc::strchr(dups, 'X'), dups);
+}