diff --git a/js/common/lib/inference-session.ts b/js/common/lib/inference-session.ts
index 4f7fbdcdcf..14db5c59d9 100644
--- a/js/common/lib/inference-session.ts
+++ b/js/common/lib/inference-session.ts
@@ -243,7 +243,7 @@ export declare namespace InferenceSession {
   }
   export interface WebNNExecutionProviderOption extends ExecutionProviderOption {
     readonly name: 'webnn';
-    deviceType?: 'cpu'|'gpu';
+    deviceType?: 'cpu'|'gpu'|'npu';
     numThreads?: number;
     powerPreference?: 'default'|'low-power'|'high-performance';
   }
diff --git a/js/web/script/test-runner-cli-args.ts b/js/web/script/test-runner-cli-args.ts
index 745f504b04..adcd940178 100644
--- a/js/web/script/test-runner-cli-args.ts
+++ b/js/web/script/test-runner-cli-args.ts
@@ -78,7 +78,7 @@ Options:
  --webgpu.<...>=<...>            --webgpu.profiling.mode=default --wasm.numThreads=1 --wasm.simd=false
  --webnn.<...>=<...>
 
- --webnn-device-type           Set the WebNN device type (cpu/gpu)
+ --webnn-device-type           Set the WebNN device type (cpu/gpu/npu)
 
  -x, --wasm-number-threads     Set the WebAssembly number of threads
                                 ("--wasm-number-threads" is deprecated. use "--wasm.numThreads" or "-x" instead)
@@ -351,7 +351,7 @@ function parseWebgpuFlags(args: minimist.ParsedArgs): Partial<Env.WebGpuFlags> {
 
 function parseWebNNOptions(args: minimist.ParsedArgs): InferenceSession.WebNNExecutionProviderOption {
   const deviceType = args['webnn-device-type'];
-  if (deviceType !== undefined && deviceType !== 'cpu' && deviceType !== 'gpu') {
+  if (deviceType !== undefined && !['cpu', 'gpu', 'npu'].includes(deviceType)) {
     throw new Error('Flag "webnn-device-type" is invalid');
   }
   return {name: 'webnn', deviceType};
diff --git a/onnxruntime/core/providers/webnn/builders/helper.h b/onnxruntime/core/providers/webnn/builders/helper.h
index d1d7804332..d35a2ae17f 100644
--- a/onnxruntime/core/providers/webnn/builders/helper.h
+++ b/onnxruntime/core/providers/webnn/builders/helper.h
@@ -28,6 +28,7 @@ namespace webnn {
 enum class WebnnDeviceType {
   CPU,
   GPU,
+  NPU,
 };
 
 typedef struct {
diff --git a/onnxruntime/core/providers/webnn/webnn_execution_provider.cc b/onnxruntime/core/providers/webnn/webnn_execution_provider.cc
index 29c8ca91fe..d72abf1a72 100644
--- a/onnxruntime/core/providers/webnn/webnn_execution_provider.cc
+++ b/onnxruntime/core/providers/webnn/webnn_execution_provider.cc
@@ -37,7 +37,13 @@ WebNNExecutionProvider::WebNNExecutionProvider(const std::string& webnn_device_f
     }
   } else {
     preferred_layout_ = DataLayout::NCHW;
-    wnn_device_type_ = webnn::WebnnDeviceType::GPU;
+    if (webnn_device_flags.compare("gpu") == 0) {
+      wnn_device_type_ = webnn::WebnnDeviceType::GPU;
+    } else if (webnn_device_flags.compare("npu") == 0) {
+      wnn_device_type_ = webnn::WebnnDeviceType::NPU;
+    } else {
+      ORT_THROW("Unknown WebNN deviceType.");
+    }
   }
   if (webnn_power_flags.compare("default") != 0) {
     context_options.set("powerPreference", emscripten::val(webnn_power_flags));