diff --git a/soc/arm/st_stm32/stm32u5/Kconfig.defconfig.stm32u5a9xx b/soc/arm/st_stm32/stm32u5/Kconfig.defconfig.stm32u5a9xx
new file mode 100644
index 00000000000..0553382acb1
--- /dev/null
+++ b/soc/arm/st_stm32/stm32u5/Kconfig.defconfig.stm32u5a9xx
@@ -0,0 +1,14 @@
+# STMicroelectronics STM32U5A9XX MCU
+
+# Copyright (c) 2023 STMicroelectronics
+# SPDX-License-Identifier: Apache-2.0
+
+if SOC_STM32U5A9XX
+
+config SOC
+	default "stm32u5a9xx"
+
+config NUM_IRQS
+	default 139
+
+endif # SOC_STM32U5A9XX
diff --git a/soc/arm/st_stm32/stm32u5/Kconfig.soc b/soc/arm/st_stm32/stm32u5/Kconfig.soc
index 8308c64372f..ec8c964ad3e 100644
--- a/soc/arm/st_stm32/stm32u5/Kconfig.soc
+++ b/soc/arm/st_stm32/stm32u5/Kconfig.soc
@@ -2,6 +2,7 @@
 
 # Copyright (c) 2021 Linaro Limited
 # Copyright (c) 2023 PSICONTROL nv
+# Copyright (c) 2023 STMicroelectronics
 # SPDX-License-Identifier: Apache-2.0
 
 choice
@@ -23,4 +24,7 @@ config SOC_STM32U599XX
 config SOC_STM32U5A5XX
 	bool "STM32U5A5XX"
 
+config SOC_STM32U5A9XX
+	bool "STM32U5A9XX"
+
 endchoice