diff --git a/samples/boards/nordic/system_off/boards/nrf54l20pdk_nrf54l20_cpuapp.overlay b/samples/boards/nordic/system_off/boards/nrf54l20pdk_nrf54l20_cpuapp.overlay
new file mode 100644
index 00000000000..3a79636a483
--- /dev/null
+++ b/samples/boards/nordic/system_off/boards/nrf54l20pdk_nrf54l20_cpuapp.overlay
@@ -0,0 +1,25 @@
+/ {
+	cpuapp_sram@2007ec00 {
+		compatible = "zephyr,memory-region", "mmio-sram";
+		reg = <0x2007ec00 DT_SIZE_K(4)>;
+		zephyr,memory-region = "RetainedMem";
+		status = "okay";
+
+		retainedmem0: retainedmem {
+			compatible = "zephyr,retained-ram";
+			status = "okay";
+		};
+	};
+
+	aliases {
+		retainedmemdevice = &retainedmem0;
+	};
+};
+
+&cpuapp_sram {
+	/* Shrink SRAM size to avoid overlap with retained memory region:
+	 * 511 - 4 = 507KB = 0x7ec00
+	 */
+	reg = <0x20000000 DT_SIZE_K(507)>;
+	ranges = <0x0 0x20000000 0x7ec00>;
+};
diff --git a/samples/boards/nordic/system_off/sample.yaml b/samples/boards/nordic/system_off/sample.yaml
index 18f629c4e54..9bdf253124e 100644
--- a/samples/boards/nordic/system_off/sample.yaml
+++ b/samples/boards/nordic/system_off/sample.yaml
@@ -14,6 +14,7 @@ tests:
       - nrf54l15dk/nrf54l05/cpuapp
       - nrf54l15dk/nrf54l10/cpuapp
       - nrf54l15dk/nrf54l15/cpuapp
+      - nrf54l20pdk/nrf54l20/cpuapp
     harness: console
     harness_config:
       type: multi_line
@@ -45,6 +46,7 @@ tests:
     extra_args: DTC_OVERLAY_FILE="boards/nrf54l15dk_nrf54l15_cpuapp_retained_mem.overlay"
     platform_allow:
       - nrf54l15dk/nrf54l15/cpuapp
+      - nrf54l20pdk/nrf54l20/cpuapp
     extra_configs:
       - CONFIG_APP_USE_RETAINED_MEM=y
       - CONFIG_RETAINED_MEM=y
@@ -62,6 +64,7 @@ tests:
   sample.boards.nrf.system_off.grtc_wakeup:
     platform_allow:
       - nrf54l15dk/nrf54l15/cpuapp
+      - nrf54l20pdk/nrf54l20/cpuapp
     extra_configs:
       - CONFIG_GRTC_WAKEUP_ENABLE=y
     harness: console
@@ -82,6 +85,7 @@ tests:
     extra_args: DTC_OVERLAY_FILE="boards/nrf54l15dk_nrf54l15_cpuapp_retained_mem.overlay"
     platform_allow:
       - nrf54l15dk/nrf54l15/cpuapp
+      - nrf54l20pdk/nrf54l20/cpuapp
     extra_configs:
       - CONFIG_APP_USE_RETAINED_MEM=y
       - CONFIG_GRTC_WAKEUP_ENABLE=y