diff --git a/boards/arm/b_u585i_iot02a/arduino_r3_connector.dtsi b/boards/arm/b_u585i_iot02a/arduino_r3_connector.dtsi
index 4bf599c616c..655669f59ca 100644
--- a/boards/arm/b_u585i_iot02a/arduino_r3_connector.dtsi
+++ b/boards/arm/b_u585i_iot02a/arduino_r3_connector.dtsi
@@ -37,3 +37,4 @@
 
 arduino_spi: &spi1 {};
 arduino_i2c: &i2c1 {};
+arduino_serial: &usart3 {};
diff --git a/boards/arm/b_u585i_iot02a/b_u585i_iot02a-common.dtsi b/boards/arm/b_u585i_iot02a/b_u585i_iot02a-common.dtsi
index 8f8738eba84..ed6a0f9673d 100644
--- a/boards/arm/b_u585i_iot02a/b_u585i_iot02a-common.dtsi
+++ b/boards/arm/b_u585i_iot02a/b_u585i_iot02a-common.dtsi
@@ -94,6 +94,13 @@
 	status = "okay";
 };
 
+&usart3 {
+	pinctrl-0 = <&usart3_tx_pd8 &usart3_rx_pd9>;
+	pinctrl-names = "default";
+	current-speed = <115200>;
+	status = "okay";
+};
+
 &spi1 {
 	pinctrl-0 = <&spi1_nss_pe12 &spi1_sck_pe13
 		     &spi1_miso_pe14 &spi1_mosi_pe15>;