diff --git a/target/linux/ramips/dts/mt7621_asus_rt-ac85u.dts b/target/linux/ramips/dts/mt7621_asus_rt-ac85u.dts
new file mode 100644
index 00000000000..92bca2e14b1
--- /dev/null
+++ b/target/linux/ramips/dts/mt7621_asus_rt-ac85u.dts
@@ -0,0 +1,233 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+
+#include "mt7621.dtsi"
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
+#include <dt-bindings/leds/common.h>
+
+/ {
+	compatible = "asus,rt-ac85u", "mediatek,mt7621-soc";
+	model = "ASUS RT-AC85U";
+
+	aliases {
+		led-boot = &led_power;
+		led-failsafe = &led_power;
+		led-running = &led_power;
+		led-upgrade = &led_power;
+		label-mac-device = &gmac0;
+	};
+
+	keys {
+		compatible = "gpio-keys";
+
+		reset {
+			label = "reset";
+			gpios = <&gpio 16 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_RESTART>;
+		};
+
+		wps {
+			label = "wps";
+			gpios = <&gpio 18 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_WPS_BUTTON>;
+		};
+	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		led_power: power {
+			function = LED_FUNCTION_POWER;
+			color = <LED_COLOR_ID_BLUE>;
+			gpios = <&gpio 6 GPIO_ACTIVE_LOW>;
+		};
+
+		wifi2g {
+			color = <LED_COLOR_ID_BLUE>;
+			function = LED_FUNCTION_WLAN_2GHZ;
+			gpios = <&gpio 4 GPIO_ACTIVE_LOW>;
+			linux,default-trigger = "phy0tpt";
+		};
+
+		wifi5g {
+			color = <LED_COLOR_ID_BLUE>;
+			function = LED_FUNCTION_WLAN_5GHZ;
+			gpios = <&gpio 7 GPIO_ACTIVE_LOW>;
+			linux,default-trigger = "phy1tpt";
+		};
+
+		wan {
+			color = <LED_COLOR_ID_BLUE>;
+			function = LED_FUNCTION_WAN;
+			gpios = <&gpio 13 GPIO_ACTIVE_LOW>;
+		};
+
+		lan {
+			color = <LED_COLOR_ID_BLUE>;
+			function = LED_FUNCTION_LAN;
+			gpios = <&gpio 14 GPIO_ACTIVE_LOW>;
+		};
+
+		usb {
+			color = <LED_COLOR_ID_BLUE>;
+			function = LED_FUNCTION_USB;
+			gpios = <&gpio 15 GPIO_ACTIVE_LOW>;
+		};
+
+		wps {
+			color = <LED_COLOR_ID_BLUE>;
+			function = LED_FUNCTION_WPS;
+			gpios = <&gpio 12 GPIO_ACTIVE_LOW>;
+		};
+	};
+};
+
+&nand {
+	status = "okay";
+
+	partitions {
+		compatible = "fixed-partitions";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		partition@0 {
+			label = "u-boot";
+			reg = <0x0 0xe0000>;
+			read-only;
+		};
+
+		partition@e0000 {
+			label = "u-boot-env";
+			reg = <0xe0000 0x100000>;
+			read-only;
+		};
+
+		partition@1e0000 {
+			label = "factory";
+			reg = <0x1e0000 0x100000>;
+			read-only;
+
+			nvmem-layout {
+				compatible = "fixed-layout";
+				#address-cells = <1>;
+				#size-cells = <1>;
+
+				eeprom_factory_0: eeprom@0 {
+					reg = <0x0 0x4da8>;
+				};
+
+				eeprom_factory_8000: eeprom@8000 {
+					reg = <0x8000 0x4da8>;
+				};
+
+				macaddr_factory_e000: macaddr@e000 {
+					reg = <0xe000 0x6>;
+				};
+			};
+		};
+
+		partition@2e0000 {
+			label = "factory2";
+			reg = <0x2e0000 0x100000>;
+			read-only;
+		};
+
+		partition@3e0000 {
+			label = "kernel";
+			reg = <0x3e0000 0x400000>;
+		};
+
+		partition@7e0000 {
+			label = "ubi";
+			reg = <0x7e0000 0x2e00000>;
+		};
+
+		partition@35e0000 {
+			label = "firmware2";
+			reg = <0x35e0000 0x3200000>;
+		};
+	};
+};
+
+&pcie {
+	status = "okay";
+};
+
+&pcie0 {
+	wifi0: wifi@0,0 {
+		compatible = "mediatek,mt76";
+		reg = <0x0000 0 0 0 0>;
+		nvmem-cells = <&eeprom_factory_0>;
+		nvmem-cell-names = "eeprom";
+		ieee80211-freq-limit = <2400000 2500000>;
+	};
+};
+
+&pcie1 {
+	wifi1: wifi@0,0 {
+		compatible = "mediatek,mt76";
+		reg = <0x0000 0 0 0 0>;
+		nvmem-cells = <&eeprom_factory_8000>;
+		nvmem-cell-names = "eeprom";
+		ieee80211-freq-limit = <5000000 6000000>;
+	};
+};
+
+
+&gmac0 {
+	nvmem-cells = <&macaddr_factory_e000>;
+	nvmem-cell-names = "mac-address";
+};
+
+&gmac1 {
+	status = "okay";
+	label = "wan";
+	phy-handle = <&ethphy4>;
+
+	nvmem-cells = <&macaddr_factory_e000>;
+	nvmem-cell-names = "mac-address";
+};
+
+&ethphy4 {
+	/delete-property/ interrupts;
+};
+
+&switch0 {
+	ports {
+		port@0 {
+			status = "okay";
+			label = "lan1";
+		};
+
+		port@1 {
+			status = "okay";
+			label = "lan2";
+		};
+
+		port@2 {
+			status = "okay";
+			label = "lan3";
+		};
+
+		port@3 {
+			status = "okay";
+			label = "lan4";
+		};
+
+		port@4 {
+			status = "disabled";
+		};
+	};
+};
+
+&state_default {
+	gpio {
+		groups = "uart2", "uart3", "i2c";
+		function = "gpio";
+	};
+};
+
+&xhci {
+	status = "okay";
+};
diff --git a/target/linux/ramips/image/mt7621.mk b/target/linux/ramips/image/mt7621.mk
index a80bede3478..96653683de6 100644
--- a/target/linux/ramips/image/mt7621.mk
+++ b/target/linux/ramips/image/mt7621.mk
@@ -458,6 +458,16 @@ define Device/asus_rt-ac85p
 endef
 TARGET_DEVICES += asus_rt-ac85p
 
+define Device/asus_rt-ac85u
+  $(Device/nand)
+  DEVICE_VENDOR := ASUS
+  DEVICE_MODEL := RT-AC85U
+  DEVICE_DTS := mt7621_asus_rt-ac85u
+  IMAGE_SIZE := 51200k
+  DEVICE_PACKAGES := kmod-usb3 kmod-mt7615-firmware uboot-envtools
+endef
+TARGET_DEVICES += asus_rt-ac85u
+
 define Device/asus_rt-n56u-b1
   $(Device/dsa-migration)
   $(Device/uimage-lzma-loader)
diff --git a/target/linux/ramips/mt7621/base-files/lib/upgrade/platform.sh b/target/linux/ramips/mt7621/base-files/lib/upgrade/platform.sh
index 52617bc4264..4e1aab27634 100644
--- a/target/linux/ramips/mt7621/base-files/lib/upgrade/platform.sh
+++ b/target/linux/ramips/mt7621/base-files/lib/upgrade/platform.sh
@@ -73,6 +73,7 @@ platform_do_upgrade() {
 	arcadyan,we420223-99|\
 	asus,rt-ac65p|\
 	asus,rt-ac85p|\
+	asus,rt-ac85u|\
 	asus,rt-ax53u|\
 	asus,rt-ax54|\
 	asus,4g-ax56|\