diff --git a/doc/releases/release-notes-4.0.rst b/doc/releases/release-notes-4.0.rst
index 24bc0df1b0668d..d3436f014f3655 100644
--- a/doc/releases/release-notes-4.0.rst
+++ b/doc/releases/release-notes-4.0.rst
@@ -24,6 +24,11 @@ https://docs.zephyrproject.org/latest/security/vulnerabilities.html
 API Changes
 ***********
 
+* Removed deprecated arch-level CMSIS header files
+  ``include/zephyr/arch/arm/cortex_a_r/cmsis.h`` and
+  ``include/zephyr/arch/arm/cortex_m/cmsis.h``. ``cmsis_core.h`` needs to be
+  included now.
+
 Removed APIs in this release
 ============================
 
diff --git a/include/zephyr/arch/arm/cortex_a_r/cmsis.h b/include/zephyr/arch/arm/cortex_a_r/cmsis.h
deleted file mode 100644
index e1e7071ef4729b..00000000000000
--- a/include/zephyr/arch/arm/cortex_a_r/cmsis.h
+++ /dev/null
@@ -1,13 +0,0 @@
-/*
- * Copyright (c) 2023 Nordic Semiconductor ASA
- * SPDX-License-Identifier: Apache-2.0
- */
-
-#ifndef ZEPHYR_ARCH_ARM_AARCH32_CORTEX_A_R_CMSIS_H_
-#define ZEPHYR_ARCH_ARM_AARCH32_CORTEX_A_R_CMSIS_H_
-
-#include <cmsis_core.h>
-
-#warning This header is deprecated, please include <cmsis_core.h>
-
-#endif /* ZEPHYR_ARCH_ARM_AARCH32_CORTEX_A_R_CMSIS_H_ */
diff --git a/include/zephyr/arch/arm/cortex_m/cmsis.h b/include/zephyr/arch/arm/cortex_m/cmsis.h
deleted file mode 100644
index c16b008c7a61e6..00000000000000
--- a/include/zephyr/arch/arm/cortex_m/cmsis.h
+++ /dev/null
@@ -1,13 +0,0 @@
-/*
- * Copyright (c) 2023 Nordic Semiconductor ASA
- * SPDX-License-Identifier: Apache-2.0
- */
-
-#ifndef ZEPHYR_ARCH_ARM_AARCH32_CORTEX_M_CMSIS_H_
-#define ZEPHYR_ARCH_ARM_AARCH32_CORTEX_M_CMSIS_H_
-
-#include <cmsis_core.h>
-
-#warning This header is deprecated, please include <cmsis_core.h>
-
-#endif /* ZEPHYR_ARCH_ARM_AARCH32_CORTEX_M_CMSIS_H_ */