diff --git a/libc/config/darwin/arm/entrypoints.txt b/libc/config/darwin/arm/entrypoints.txt
--- a/libc/config/darwin/arm/entrypoints.txt
+++ b/libc/config/darwin/arm/entrypoints.txt
@@ -54,6 +54,7 @@
     libc.src.string.strndup
 
     # inttypes.h entrypoints
+    libc.src.inttypes.imaxabs
     libc.src.inttypes.imaxdiv
     libc.src.inttypes.strtoimax
     libc.src.inttypes.strtoumax
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
@@ -59,6 +59,7 @@
     libc.src.string.strndup
 
     # inttypes.h entrypoints
+    libc.src.inttypes.imaxabs
     libc.src.inttypes.imaxdiv
     libc.src.inttypes.strtoimax
     libc.src.inttypes.strtoumax
diff --git a/libc/config/linux/arm/entrypoints.txt b/libc/config/linux/arm/entrypoints.txt
--- a/libc/config/linux/arm/entrypoints.txt
+++ b/libc/config/linux/arm/entrypoints.txt
@@ -39,6 +39,7 @@
     libc.src.string.strtok_r
  
     # inttypes.h entrypoints
+    libc.src.inttypes.imaxabs
     libc.src.inttypes.imaxdiv
     libc.src.inttypes.strtoimax
     libc.src.inttypes.strtoumax
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
@@ -59,6 +59,7 @@
     libc.src.string.strndup
 
     # inttypes.h entrypoints
+    libc.src.inttypes.imaxabs
     libc.src.inttypes.imaxdiv
     libc.src.inttypes.strtoimax
     libc.src.inttypes.strtoumax
diff --git a/libc/config/windows/entrypoints.txt b/libc/config/windows/entrypoints.txt
--- a/libc/config/windows/entrypoints.txt
+++ b/libc/config/windows/entrypoints.txt
@@ -54,6 +54,7 @@
     libc.src.string.strndup
 
     # inttypes.h entrypoints
+    libc.src.inttypes.imaxabs
     libc.src.inttypes.imaxdiv
     libc.src.inttypes.strtoimax
     libc.src.inttypes.strtoumax
diff --git a/libc/src/inttypes/CMakeLists.txt b/libc/src/inttypes/CMakeLists.txt
--- a/libc/src/inttypes/CMakeLists.txt
+++ b/libc/src/inttypes/CMakeLists.txt
@@ -28,3 +28,14 @@
     libc.include.inttypes
     libc.src.__support.integer_operations
 )
+
+add_entrypoint_object(
+  imaxabs
+  SRCS
+    imaxabs.cpp
+  HDRS
+    imaxabs.h
+  DEPENDS
+    libc.include.inttypes
+    libc.src.__support.integer_operations
+)
diff --git a/libc/src/inttypes/imaxabs.h b/libc/src/inttypes/imaxabs.h
new file mode 100644
--- /dev/null
+++ b/libc/src/inttypes/imaxabs.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for imaxabs -----------------------*- 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_INTTYPES_IMAXABS_H
+#define LLVM_LIBC_SRC_INTTYPES_IMAXABS_H
+
+#include <inttypes.h>
+
+namespace __llvm_libc {
+
+intmax_t imaxabs(intmax_t j);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_INTTYPES_IMAXABS_H
diff --git a/libc/src/inttypes/imaxabs.cpp b/libc/src/inttypes/imaxabs.cpp
new file mode 100644
--- /dev/null
+++ b/libc/src/inttypes/imaxabs.cpp
@@ -0,0 +1,17 @@
+//===-- Implementation of imaxabs -----------------------------------------===//
+//
+// 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/inttypes/imaxabs.h"
+#include "src/__support/common.h"
+#include "src/__support/integer_operations.h"
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(intmax_t, imaxabs, (intmax_t j)) { return integer_abs(j); }
+
+} // namespace __llvm_libc
diff --git a/libc/test/src/inttypes/CMakeLists.txt b/libc/test/src/inttypes/CMakeLists.txt
--- a/libc/test/src/inttypes/CMakeLists.txt
+++ b/libc/test/src/inttypes/CMakeLists.txt
@@ -32,3 +32,17 @@
     libc.include.stdlib
     libc.src.inttypes.imaxdiv
 )
+
+add_libc_unittest(
+  imaxabs_test
+  SUITE
+    libc_inttypes_unittests
+  SRCS
+    imaxabs_test.cpp
+  HDRS
+    ../stdlib/DivTest.h
+  DEPENDS
+    libc.include.stdlib
+    libc.src.inttypes.imaxabs
+)
+
diff --git a/libc/test/src/inttypes/imaxabs_test.cpp b/libc/test/src/inttypes/imaxabs_test.cpp
new file mode 100644
--- /dev/null
+++ b/libc/test/src/inttypes/imaxabs_test.cpp
@@ -0,0 +1,22 @@
+//===-- Unittests for imaxabs ---------------------------------------------===//
+//
+// 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/inttypes/imaxabs.h"
+#include "utils/UnitTest/Test.h"
+
+TEST(LlvmLibcImaxAbsTest, Zero) {
+  EXPECT_EQ(__llvm_libc::imaxabs(0), intmax_t(0));
+}
+
+TEST(LlvmLibcImaxAbsTest, Positive) {
+  EXPECT_EQ(__llvm_libc::imaxabs(1), intmax_t(1));
+}
+
+TEST(LlvmLibcImaxAbsTest, Negative) {
+  EXPECT_EQ(__llvm_libc::imaxabs(-1), intmax_t(1));
+}