diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c
index 151f356224..02c72d06b7 100644
--- a/app/test-pmd/cmdline.c
+++ b/app/test-pmd/cmdline.c
@@ -653,7 +653,7 @@ static void cmd_help_long_parsed(void *parsed_result,
 			"    Detach physical or virtual dev by port_id\n\n"
 
 			"port config (port_id|all)"
-			" speed (10|100|1000|10000|25000|40000|50000|100000|200000|auto)"
+			" speed (10|100|1000|10000|25000|40000|50000|100000|200000|400000|auto)"
 			" duplex (half|full|auto)\n"
 			"    Set speed and duplex for all ports or port_id\n\n"
 
@@ -1356,6 +1356,8 @@ parse_and_check_speed_duplex(char *speedstr, char *duplexstr, uint32_t *speed)
 			*speed = RTE_ETH_LINK_SPEED_100G;
 		} else if (!strcmp(speedstr, "200000")) {
 			*speed = RTE_ETH_LINK_SPEED_200G;
+		} else if (!strcmp(speedstr, "400000")) {
+			*speed = RTE_ETH_LINK_SPEED_400G;
 		} else if (!strcmp(speedstr, "auto")) {
 			*speed = RTE_ETH_LINK_SPEED_AUTONEG;
 		} else {
@@ -1406,7 +1408,7 @@ static cmdline_parse_token_string_t cmd_config_speed_all_item1 =
 	TOKEN_STRING_INITIALIZER(struct cmd_config_speed_all, item1, "speed");
 static cmdline_parse_token_string_t cmd_config_speed_all_value1 =
 	TOKEN_STRING_INITIALIZER(struct cmd_config_speed_all, value1,
-				"10#100#1000#10000#25000#40000#50000#100000#200000#auto");
+				"10#100#1000#10000#25000#40000#50000#100000#200000#400000#auto");
 static cmdline_parse_token_string_t cmd_config_speed_all_item2 =
 	TOKEN_STRING_INITIALIZER(struct cmd_config_speed_all, item2, "duplex");
 static cmdline_parse_token_string_t cmd_config_speed_all_value2 =
@@ -1417,7 +1419,7 @@ static cmdline_parse_inst_t cmd_config_speed_all = {
 	.f = cmd_config_speed_all_parsed,
 	.data = NULL,
 	.help_str = "port config all speed "
-		"10|100|1000|10000|25000|40000|50000|100000|200000|auto duplex "
+		"10|100|1000|10000|25000|40000|50000|100000|200000|400000|auto duplex "
 							"half|full|auto",
 	.tokens = {
 		(void *)&cmd_config_speed_all_port,
@@ -1481,7 +1483,7 @@ static cmdline_parse_token_string_t cmd_config_speed_specific_item1 =
 								"speed");
 static cmdline_parse_token_string_t cmd_config_speed_specific_value1 =
 	TOKEN_STRING_INITIALIZER(struct cmd_config_speed_specific, value1,
-				"10#100#1000#10000#25000#40000#50000#100000#200000#auto");
+				"10#100#1000#10000#25000#40000#50000#100000#200000#400000#auto");
 static cmdline_parse_token_string_t cmd_config_speed_specific_item2 =
 	TOKEN_STRING_INITIALIZER(struct cmd_config_speed_specific, item2,
 								"duplex");
@@ -1493,7 +1495,7 @@ static cmdline_parse_inst_t cmd_config_speed_specific = {
 	.f = cmd_config_speed_specific_parsed,
 	.data = NULL,
 	.help_str = "port config <port_id> speed "
-		"10|100|1000|10000|25000|40000|50000|100000|200000|auto duplex "
+		"10|100|1000|10000|25000|40000|50000|100000|200000|400000|auto duplex "
 							"half|full|auto",
 	.tokens = {
 		(void *)&cmd_config_speed_specific_port,
diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c
index 4121c5c9bb..018536f177 100644
--- a/app/test-pmd/config.c
+++ b/app/test-pmd/config.c
@@ -612,6 +612,8 @@ device_infos_display_speeds(uint32_t speed_capa)
 		printf(" 100 Gbps  ");
 	if (speed_capa & RTE_ETH_LINK_SPEED_200G)
 		printf(" 200 Gbps  ");
+	if (speed_capa & RTE_ETH_LINK_SPEED_400G)
+		printf(" 400 Gbps  ");
 }
 
 void
diff --git a/app/test-pmd/parameters.c b/app/test-pmd/parameters.c
index e734ad9a02..3b37809baf 100644
--- a/app/test-pmd/parameters.c
+++ b/app/test-pmd/parameters.c
@@ -568,6 +568,9 @@ parse_link_speed(int n)
 	case 200000:
 		speed |= RTE_ETH_LINK_SPEED_200G;
 		break;
+	case 400000:
+		speed |= RTE_ETH_LINK_SPEED_400G;
+		break;
 	case 100:
 	case 10:
 	default:
diff --git a/app/test/test_ethdev_link.c b/app/test/test_ethdev_link.c
index 6248aea49a..ab52385a12 100644
--- a/app/test/test_ethdev_link.c
+++ b/app/test/test_ethdev_link.c
@@ -54,7 +54,7 @@ test_link_status_up_default(void)
 		"string with HDX");
 
 	/* test max str len */
-	link_status.link_speed = RTE_ETH_SPEED_NUM_200G;
+	link_status.link_speed = RTE_ETH_SPEED_NUM_400G;
 	link_status.link_duplex = RTE_ETH_LINK_HALF_DUPLEX;
 	link_status.link_autoneg = RTE_ETH_LINK_AUTONEG;
 	ret = rte_eth_link_to_str(text, sizeof(text), &link_status);
@@ -130,6 +130,7 @@ test_link_speed_all_values(void)
 		{ "56 Gbps",  RTE_ETH_SPEED_NUM_56G },
 		{ "100 Gbps", RTE_ETH_SPEED_NUM_100G },
 		{ "200 Gbps", RTE_ETH_SPEED_NUM_200G },
+		{ "400 Gbps", RTE_ETH_SPEED_NUM_400G },
 		{ "Unknown",  RTE_ETH_SPEED_NUM_UNKNOWN },
 		{ "Invalid",   50505 }
 	};
diff --git a/doc/guides/rel_notes/release_23_03.rst b/doc/guides/rel_notes/release_23_03.rst
index 49c18617a5..ef2629a1ca 100644
--- a/doc/guides/rel_notes/release_23_03.rst
+++ b/doc/guides/rel_notes/release_23_03.rst
@@ -73,6 +73,8 @@ New Features
   Added power monitor and wake up API support
   with WFE/SVE instructions for Arm architecture.
 
+* **Added Ethernet link speed for 400 Gb/s.**
+
 * **Added support for mapping a queue with an aggregated port.**
 
   * Introduced new function ``rte_eth_dev_count_aggr_ports()``
diff --git a/doc/guides/testpmd_app_ug/run_app.rst b/doc/guides/testpmd_app_ug/run_app.rst
index f85f323033..57b23241cf 100644
--- a/doc/guides/testpmd_app_ug/run_app.rst
+++ b/doc/guides/testpmd_app_ug/run_app.rst
@@ -394,6 +394,7 @@ The command line options are:
        50000 - 50Gbps
        100000 - 100Gbps
        200000 - 200Gbps
+       400000 - 400Gbps
        ...
 
 *   ``--disable-link-check``
diff --git a/doc/guides/testpmd_app_ug/testpmd_funcs.rst b/doc/guides/testpmd_app_ug/testpmd_funcs.rst
index 5a88933635..8f23847859 100644
--- a/doc/guides/testpmd_app_ug/testpmd_funcs.rst
+++ b/doc/guides/testpmd_app_ug/testpmd_funcs.rst
@@ -2048,7 +2048,7 @@ port config - speed
 
 Set the speed and duplex mode for all ports or a specific port::
 
-   testpmd> port config (port_id|all) speed (10|100|1000|10000|25000|40000|50000|100000|200000|auto) \
+   testpmd> port config (port_id|all) speed (10|100|1000|10000|25000|40000|50000|100000|200000|400000|auto) \
             duplex (half|full|auto)
 
 port config - queues/descriptors
diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index 0103d95920..dc6856d749 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -2046,6 +2046,8 @@ virtio_dev_speed_capa_get(uint32_t speed)
 		return RTE_ETH_LINK_SPEED_100G;
 	case RTE_ETH_SPEED_NUM_200G:
 		return RTE_ETH_LINK_SPEED_200G;
+	case RTE_ETH_SPEED_NUM_400G:
+		return RTE_ETH_LINK_SPEED_400G;
 	default:
 		return 0;
 	}
diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
index 0266cc82ac..3814c202cd 100644
--- a/lib/ethdev/rte_ethdev.c
+++ b/lib/ethdev/rte_ethdev.c
@@ -978,6 +978,9 @@ rte_eth_speed_bitflag(uint32_t speed, int duplex)
 	case RTE_ETH_SPEED_NUM_200G:
 		ret = RTE_ETH_LINK_SPEED_200G;
 		break;
+	case RTE_ETH_SPEED_NUM_400G:
+		ret = RTE_ETH_LINK_SPEED_400G;
+		break;
 	default:
 		ret = 0;
 	}
@@ -2882,6 +2885,9 @@ rte_eth_link_speed_to_str(uint32_t link_speed)
 	case RTE_ETH_SPEED_NUM_200G:
 		ret = "200 Gbps";
 		break;
+	case RTE_ETH_SPEED_NUM_400G:
+		ret = "400 Gbps";
+		break;
 	case RTE_ETH_SPEED_NUM_UNKNOWN:
 		ret = "Unknown";
 		break;
diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
index 049641d57c..d40cb22dae 100644
--- a/lib/ethdev/rte_ethdev.h
+++ b/lib/ethdev/rte_ethdev.h
@@ -304,6 +304,7 @@ struct rte_eth_stats {
 #define RTE_ETH_LINK_SPEED_56G     RTE_BIT32(13) /**<  56 Gbps */
 #define RTE_ETH_LINK_SPEED_100G    RTE_BIT32(14) /**< 100 Gbps */
 #define RTE_ETH_LINK_SPEED_200G    RTE_BIT32(15) /**< 200 Gbps */
+#define RTE_ETH_LINK_SPEED_400G    RTE_BIT32(16) /**< 400 Gbps */
 /**@}*/
 
 /**@{@name Link speed
@@ -323,6 +324,7 @@ struct rte_eth_stats {
 #define RTE_ETH_SPEED_NUM_56G      56000 /**<  56 Gbps */
 #define RTE_ETH_SPEED_NUM_100G    100000 /**< 100 Gbps */
 #define RTE_ETH_SPEED_NUM_200G    200000 /**< 200 Gbps */
+#define RTE_ETH_SPEED_NUM_400G    400000 /**< 400 Gbps */
 #define RTE_ETH_SPEED_NUM_UNKNOWN UINT32_MAX /**< Unknown */
 /**@}*/
 
