diff --git a/soc/arm/st_stm32/stm32l4/Kconfig.defconfig.stm32l4s5xx b/soc/arm/st_stm32/stm32l4/Kconfig.defconfig.stm32l4s5xx
new file mode 100644
index 00000000000..79d97dbe083
--- /dev/null
+++ b/soc/arm/st_stm32/stm32l4/Kconfig.defconfig.stm32l4s5xx
@@ -0,0 +1,14 @@
+# ST Microelectronics STM32L4S5xx MCU
+
+# Copyright (c) 2020 STMicroelectronics
+# SPDX-License-Identifier: Apache-2.0
+
+if SOC_STM32L4S5XX
+
+config SOC
+	default "stm32l4s5xx"
+
+config NUM_IRQS
+	default 95
+
+endif # SOC_STM32L4S5XX
diff --git a/soc/arm/st_stm32/stm32l4/Kconfig.soc b/soc/arm/st_stm32/stm32l4/Kconfig.soc
index f65843e3dab..18e12d3f2ce 100644
--- a/soc/arm/st_stm32/stm32l4/Kconfig.soc
+++ b/soc/arm/st_stm32/stm32l4/Kconfig.soc
@@ -34,6 +34,9 @@ config SOC_STM32L462XX
 config SOC_STM32L475XX
 	bool "STM32L475XX"
 
+config SOC_STM32L4S5XX
+	bool "STM32L4S5XX"
+
 config SOC_STM32L4R5XX
 	bool "STM32L4R5XX"