diff --git a/include/onnxruntime/core/providers/utils/ort_graph_to_proto.h b/include/onnxruntime/core/providers/utils/ort_graph_to_proto.h
index 0d920ab7dac89..21aa797ce16eb 100644
--- a/include/onnxruntime/core/providers/utils/ort_graph_to_proto.h
+++ b/include/onnxruntime/core/providers/utils/ort_graph_to_proto.h
@@ -232,7 +232,7 @@ static Ort::Status GetOrtValueInfoTensorTypeShape(const OrtValueInfo& ort_value_
                                                   /*out*/ std::vector<int64_t>& dims,
                                                   /*out*/ std::vector<std::string>& symbolic_dims);
 static Ort::Status OrtValueInfoToProto(const OrtValueInfo& ort_value_info, onnx::ValueInfoProto& value_info_proto);
-static Ort::Status OrtOpAttrToProto(const OrtOpAttr& ort_attr, onnx::AttributeProto& attr_proto);
+static Ort::Status OrtOpAttrToProto(const OrtNode& ort_node, const OrtOpAttr& ort_attr, onnx::AttributeProto& attr_proto);
 
 Ort::Status OrtGraphToProto(const OrtGraph& ort_graph,
                             onnx::GraphProto& graph_proto,
@@ -379,7 +379,7 @@ Ort::Status OrtGraphToProto(const OrtGraph& ort_graph,
         }
 
         onnx::AttributeProto* attr_proto = node_proto->add_attribute();
-        ORT_EP_UTILS_CXX_RETURN_IF_ERROR(OrtOpAttrToProto(*ort_attr, *attr_proto));
+        ORT_EP_UTILS_CXX_RETURN_IF_ERROR(OrtOpAttrToProto(*ort_node, *ort_attr, *attr_proto));
       }
     }
 
@@ -652,7 +652,7 @@ static Ort::Status OrtValueInfoToProto(const OrtValueInfo& ort_value_info,
   return Ort::Status{nullptr};
 }
 
-static Ort::Status OrtOpAttrToProto(const OrtOpAttr& ort_attr, onnx::AttributeProto& attr_proto) {
+static Ort::Status OrtOpAttrToProto(const OrtNode& ort_node, const OrtOpAttr& ort_attr, onnx::AttributeProto& attr_proto) {
   const OrtApi& ort_api = Ort::GetApi();
 
   const char* attr_name = nullptr;
@@ -758,6 +758,103 @@ static Ort::Status OrtOpAttrToProto(const OrtOpAttr& ort_attr, onnx::AttributePr
 
       break;
     }
+    case OrtOpAttrType::ORT_OP_ATTR_TENSOR: {
+      attr_proto.set_type(onnx::AttributeProto_AttributeType_TENSOR);
+
+      onnx::TensorProto tensor_proto;
+
+      // TensorProto as an attribute value doesn't require a name.
+
+      OrtValue* ort_value = nullptr;
+      ORT_EP_UTILS_C_RETURN_IF_ERROR(ort_api.Node_GetTensorAttributeAsOrtValue(&ort_node, &ort_attr, &ort_value));
+
+      Ort::Value tensor(ort_value);
+
+      // Get tensor type and shape info
+      Ort::TensorTypeAndShapeInfo type_shape_info = tensor.GetTensorTypeAndShapeInfo();
+
+      // Get tensor type
+      ONNXTensorElementDataType element_type = type_shape_info.GetElementType();
+
+      size_t element_size = 0;
+      switch (element_type) {
+        case ONNX_TENSOR_ELEMENT_DATA_TYPE_FLOAT: {
+          tensor_proto.set_data_type(onnx::TensorProto_DataType_FLOAT);
+          element_size = sizeof(float);
+          break;
+        }
+        case ONNX_TENSOR_ELEMENT_DATA_TYPE_UINT8: {
+          tensor_proto.set_data_type(onnx::TensorProto_DataType_UINT8);
+          element_size = sizeof(uint8_t);
+          break;
+        }
+        case ONNX_TENSOR_ELEMENT_DATA_TYPE_INT8: {
+          tensor_proto.set_data_type(onnx::TensorProto_DataType_INT8);
+          element_size = sizeof(int8_t);
+          break;
+        }
+        case ONNX_TENSOR_ELEMENT_DATA_TYPE_UINT16: {
+          tensor_proto.set_data_type(onnx::TensorProto_DataType_UINT16);
+          element_size = sizeof(uint16_t);
+          break;
+        }
+        case ONNX_TENSOR_ELEMENT_DATA_TYPE_INT16: {
+          tensor_proto.set_data_type(onnx::TensorProto_DataType_INT16);
+          element_size = sizeof(int16_t);
+          break;
+        }
+        case ONNX_TENSOR_ELEMENT_DATA_TYPE_INT32: {
+          tensor_proto.set_data_type(onnx::TensorProto_DataType_INT32);
+          element_size = sizeof(int32_t);
+          break;
+        }
+        case ONNX_TENSOR_ELEMENT_DATA_TYPE_INT64: {
+          tensor_proto.set_data_type(onnx::TensorProto_DataType_INT64);
+          element_size = sizeof(int64_t);
+          break;
+        }
+        case ONNX_TENSOR_ELEMENT_DATA_TYPE_BOOL: {
+          tensor_proto.set_data_type(onnx::TensorProto_DataType_BOOL);
+          element_size = sizeof(bool);
+          break;
+        }
+        case ONNX_TENSOR_ELEMENT_DATA_TYPE_DOUBLE: {
+          tensor_proto.set_data_type(onnx::TensorProto_DataType_DOUBLE);
+          element_size = sizeof(double);
+          break;
+        }
+        case ONNX_TENSOR_ELEMENT_DATA_TYPE_UINT32: {
+          tensor_proto.set_data_type(onnx::TensorProto_DataType_UINT32);
+          element_size = sizeof(uint32_t);
+          break;
+        }
+        case ONNX_TENSOR_ELEMENT_DATA_TYPE_UINT64: {
+          tensor_proto.set_data_type(onnx::TensorProto_DataType_UINT64);
+          element_size = sizeof(uint64_t);
+          break;
+        }
+        default: {
+          std::string err_msg = "Unexpected ONNXTensorElementDataType with value " + std::to_string(static_cast<int>(element_type));
+          return Ort::Status(err_msg.c_str(), ORT_FAIL);
+        }
+      }
+
+      auto shape = type_shape_info.GetShape();
+
+      for (auto& dim : shape) {
+        tensor_proto.add_dims(dim);
+      }
+
+      size_t element_count = type_shape_info.GetElementCount();
+      size_t data_bytes = element_count * element_size;
+      const void* data = tensor.GetTensorData<void>();
+
+      // Copy the Ortvalue to TensorProto as raw data
+      tensor_proto.set_raw_data(data, data_bytes);
+
+      *(attr_proto.mutable_t()) = std::move(tensor_proto);
+      break;
+    }
     default: {
       std::string err_msg = "Unexpected OrtOpAttrType with value " + std::to_string(static_cast<int>(attr_type));
       return Ort::Status(err_msg.c_str(), ORT_FAIL);
diff --git a/include/onnxruntime/core/session/onnxruntime_c_api.h b/include/onnxruntime/core/session/onnxruntime_c_api.h
index cf5ad29b03801..2899a219bdda0 100644
--- a/include/onnxruntime/core/session/onnxruntime_c_api.h
+++ b/include/onnxruntime/core/session/onnxruntime_c_api.h
@@ -276,6 +276,7 @@ typedef enum OrtOpAttrType {
   ORT_OP_ATTR_STRING,
   ORT_OP_ATTR_STRINGS,
   ORT_OP_ATTR_GRAPH,
+  ORT_OP_ATTR_TENSOR,
 } OrtOpAttrType;
 
 //! @}
@@ -6065,6 +6066,20 @@ struct OrtApi {
   ORT_API2_STATUS(Node_GetAttributeByName, _In_ const OrtNode* node, _In_ const char* attribute_name,
                   _Outptr_result_maybenull_ const OrtOpAttr** attribute);
 
+  /** \brief Get the OrtNode's 'TENSOR' attribute as an OrtValue.
+   *
+   * \param[in] node The OrtNode instance.
+   * \param[in] attribute The OrtOpAttr instance.
+   * \param[out] attr_tensor If successful, contains the 'TENSOR' attribute as a newly created OrtValue.
+                             Must be freed with OrtApi::ReleaseValue.
+   *
+   * \snippet{doc} snippets.dox OrtStatus Return Value
+   *
+   * \since Version 1.23.
+   */
+  ORT_API2_STATUS(Node_GetTensorAttributeAsOrtValue, _In_ const OrtNode* node, _In_ const OrtOpAttr* attribute,
+                  _Outptr_result_maybenull_ OrtValue** attr_tensor);
+
   /** \brief Get the attribute type as OrtOpAttrType from an OrtOpAttr.
    *
    * \param[in] attribute The OrtOpAttr instance.
diff --git a/onnxruntime/core/graph/abi_graph_types.h b/onnxruntime/core/graph/abi_graph_types.h
index 6383d29d7a2bc..504b102e782fd 100644
--- a/onnxruntime/core/graph/abi_graph_types.h
+++ b/onnxruntime/core/graph/abi_graph_types.h
@@ -251,6 +251,16 @@ struct OrtNode {
   /// <returns>A status indicating success or an error.</returns>
   virtual onnxruntime::Status GetAttributes(gsl::span<const OrtOpAttr*> attrs) const = 0;
 
+  /// <summary>
+  /// Gets the node's 'TENSOR' attribute as an OrtValue.
+  /// </summary>
+  /// <param name="attr">Node's 'TENSOR' attribute.</param>
+  /// <param name="value">Output parameter is set to a newly created OrtValue containing the 'TENSOR' attribute value,
+  ///                     only if the attribute is of type 'TENSOR'</param>
+  /// <returns>A status indicating success or an error.</returns>
+  virtual onnxruntime::Status GetTensorAttributeAsOrtValue(const OrtOpAttr* attr,
+                                                           OrtValue*& value) const = 0;
+
   /// <summary>
   /// Gets the number of node subgraphs.
   /// </summary>
diff --git a/onnxruntime/core/graph/ep_api_types.cc b/onnxruntime/core/graph/ep_api_types.cc
index 493fbff897af8..eb7fb6937c29e 100644
--- a/onnxruntime/core/graph/ep_api_types.cc
+++ b/onnxruntime/core/graph/ep_api_types.cc
@@ -248,6 +248,32 @@ Status EpNode::GetAttributes(gsl::span<const OrtOpAttr*> dst) const {
   return Status::OK();
 }
 
+Status EpNode::GetTensorAttributeAsOrtValue(const OrtOpAttr* attribute, OrtValue*& result) const {
+  const auto* attr_proto = reinterpret_cast<const ONNX_NAMESPACE::AttributeProto*>(attribute);
+
+  if (attr_proto->type() != onnx::AttributeProto::TENSOR) {
+    return ORT_MAKE_STATUS(ONNXRUNTIME, FAIL, "This OrtOpAttr instance is not a 'TENSOR' attribute");
+  }
+
+  const auto& graph_viewer = ep_graph_->GetGraphViewer();
+  const auto& tensor_proto = attr_proto->t();
+
+  // Check that TensorProto is valid.
+  ORT_ENFORCE(utils::HasDataType(tensor_proto), "Tensor proto doesn't have data type.");
+  ORT_ENFORCE(ONNX_NAMESPACE::TensorProto::DataType_IsValid(tensor_proto.data_type()), "Tensor proto has invalid data type.");
+  ORT_ENFORCE(!utils::HasExternalData(tensor_proto),
+              "Tensor proto with external data for value attribute is not supported.");
+
+  // Initialize OrtValue for tensor attribute.
+  auto tensor_attribute_value = std::make_unique<OrtValue>();
+  AllocatorPtr tensor_attribute_allocator = CPUAllocator::DefaultInstance();
+  ORT_RETURN_IF_ERROR(utils::TensorProtoToOrtValue(Env::Default(), graph_viewer.ModelPath(), tensor_proto,
+                                                   tensor_attribute_allocator, *tensor_attribute_value));
+
+  result = tensor_attribute_value.release();
+  return Status::OK();
+}
+
 Status EpNode::GetNumSubgraphs(size_t& num_subgraphs) const {
   num_subgraphs = subgraphs_.size();
   return Status::OK();
diff --git a/onnxruntime/core/graph/ep_api_types.h b/onnxruntime/core/graph/ep_api_types.h
index e61bb4d62dba6..be78d77360cb8 100644
--- a/onnxruntime/core/graph/ep_api_types.h
+++ b/onnxruntime/core/graph/ep_api_types.h
@@ -183,6 +183,9 @@ struct EpNode : public OrtNode {
   // Gets the node's attributes.
   Status GetAttributes(gsl::span<const OrtOpAttr*> attrs) const override;
 
+  Status GetTensorAttributeAsOrtValue(const OrtOpAttr* attribute,
+                                      OrtValue*& attr_tensor) const override;
+
   // Gets the number of subgraphs contained by this node.
   Status GetNumSubgraphs(size_t& num_subgraphs) const override;
 
diff --git a/onnxruntime/core/graph/model_editor_api_types.h b/onnxruntime/core/graph/model_editor_api_types.h
index 5d84e48182bfe..d3795d911b22f 100644
--- a/onnxruntime/core/graph/model_editor_api_types.h
+++ b/onnxruntime/core/graph/model_editor_api_types.h
@@ -137,6 +137,11 @@ struct ModelEditorNode : public OrtNode {
                            "OrtModelEditorApi does not support getting attribute OrtOpAttr for OrtNode");
   }
 
+  Status GetTensorAttributeAsOrtValue(const OrtOpAttr* /*attribute*/, OrtValue*& /*attr_tensor*/) const override {
+    return ORT_MAKE_STATUS(ONNXRUNTIME, NOT_IMPLEMENTED,
+                           "OrtModelEditorApi does not support getting 'TENSOR' attribute for OrtNode");
+  }
+
   Status GetNumSubgraphs(size_t& /*num_subgraphs*/) const override {
     return ORT_MAKE_STATUS(ONNXRUNTIME, NOT_IMPLEMENTED,
                            "OrtModelEditorApi does not support getting the subgraphs for OrtNode");
diff --git a/onnxruntime/core/session/onnxruntime_c_api.cc b/onnxruntime/core/session/onnxruntime_c_api.cc
index ae9a86aa923fc..4c7b4d7b29c2f 100644
--- a/onnxruntime/core/session/onnxruntime_c_api.cc
+++ b/onnxruntime/core/session/onnxruntime_c_api.cc
@@ -3018,6 +3018,20 @@ ORT_API_STATUS_IMPL(OrtApis::Node_GetAttributeByName, _In_ const OrtNode* node,
   API_IMPL_END
 }
 
+ORT_API_STATUS_IMPL(OrtApis::Node_GetTensorAttributeAsOrtValue, _In_ const OrtNode* node, _In_ const OrtOpAttr* attribute, _Outptr_result_maybenull_ OrtValue** attr_tensor) {
+  API_IMPL_BEGIN
+  if (attr_tensor == nullptr) {
+    return OrtApis::CreateStatus(ORT_INVALID_ARGUMENT, "attr_tensor argument is null");
+  }
+  if (attribute == nullptr) {
+    return OrtApis::CreateStatus(ORT_INVALID_ARGUMENT, "attribute argument is null");
+  }
+
+  ORT_API_RETURN_IF_STATUS_NOT_OK(node->GetTensorAttributeAsOrtValue(attribute, *attr_tensor));
+  return nullptr;
+  API_IMPL_END
+}
+
 ORT_API_STATUS_IMPL(OrtApis::OpAttr_GetType, _In_ const OrtOpAttr* attribute, _Out_ OrtOpAttrType* type) {
   API_IMPL_BEGIN
   const auto attr = attribute->attr_proto;
@@ -3055,6 +3069,10 @@ ORT_API_STATUS_IMPL(OrtApis::OpAttr_GetType, _In_ const OrtOpAttr* attribute, _O
       *type = OrtOpAttrType::ORT_OP_ATTR_GRAPH;
       break;
     }
+    case ONNX_NAMESPACE::AttributeProto_AttributeType::AttributeProto_AttributeType_TENSOR: {
+      *type = OrtOpAttrType::ORT_OP_ATTR_TENSOR;
+      break;
+    }
     default:
       return OrtApis::CreateStatus(OrtErrorCode::ORT_INVALID_ARGUMENT, "Unexpected attribute type.");
   }
@@ -4037,6 +4055,7 @@ static constexpr OrtApi ort_api_1_to_23 = {
     &OrtApis::Node_GetNumAttributes,
     &OrtApis::Node_GetAttributes,
     &OrtApis::Node_GetAttributeByName,
+    &OrtApis::Node_GetTensorAttributeAsOrtValue,
     &OrtApis::OpAttr_GetType,
     &OrtApis::OpAttr_GetName,
     &OrtApis::Node_GetNumSubgraphs,
diff --git a/onnxruntime/core/session/ort_apis.h b/onnxruntime/core/session/ort_apis.h
index 9636c41938a2b..3eee174ff81f4 100644
--- a/onnxruntime/core/session/ort_apis.h
+++ b/onnxruntime/core/session/ort_apis.h
@@ -679,6 +679,8 @@ ORT_API_STATUS_IMPL(Node_GetAttributes, _In_ const OrtNode* node,
                     _Out_writes_(num_attributes) const OrtOpAttr** attributes, _In_ size_t num_attributes);
 ORT_API_STATUS_IMPL(Node_GetAttributeByName, _In_ const OrtNode* node, _In_ const char* attribute_name,
                     _Outptr_result_maybenull_ const OrtOpAttr** attribute);
+ORT_API_STATUS_IMPL(Node_GetTensorAttributeAsOrtValue, _In_ const OrtNode* node, _In_ const OrtOpAttr* attribute,
+                    _Outptr_result_maybenull_ OrtValue** attr_tensor);
 ORT_API_STATUS_IMPL(OpAttr_GetType, _In_ const OrtOpAttr* attribute, _Out_ OrtOpAttrType* type);
 ORT_API_STATUS_IMPL(OpAttr_GetName, _In_ const OrtOpAttr* attribute, _Outptr_ const char** name);
 ORT_API_STATUS_IMPL(Node_GetNumSubgraphs, _In_ const OrtNode* node, _Out_ size_t* num_subgraphs);
diff --git a/onnxruntime/test/ep_graph/test_ep_graph.cc b/onnxruntime/test/ep_graph/test_ep_graph.cc
index bdbc60c1a0c48..188edad572182 100644
--- a/onnxruntime/test/ep_graph/test_ep_graph.cc
+++ b/onnxruntime/test/ep_graph/test_ep_graph.cc
@@ -306,6 +306,39 @@ static void RunMNISTModel(const ORTCHAR_T* model_path, std::vector<float>& outpu
   output_data.assign(output_values, output_values + num_output_elems);
 }
 
+static void RunConstantOfShapeModel(const ORTCHAR_T* model_path, std::vector<float>& output_data) {
+  auto memory_info = Ort::MemoryInfo::CreateCpu(OrtDeviceAllocator, OrtMemTypeCPU);
+  Ort::SessionOptions sess_options;
+  Ort::Session session(*ort_env, model_path, sess_options);
+
+  std::vector<int64_t> input_shape = {3};
+  std::vector<int64_t> input_data = {2, 3, 4};
+  std::vector<Ort::Value> ort_inputs;
+  std::vector<const char*> ort_input_names;
+
+  // Add 'x'
+  ort_inputs.emplace_back(Ort::Value::CreateTensor<int64_t>(
+      memory_info, input_data.data(), input_data.size(), input_shape.data(), input_shape.size()));
+  ort_input_names.push_back("x");
+
+  // Run session and get outputs
+  std::array<const char*, 1> output_names{"y"};
+  std::vector<Ort::Value> ort_outputs = session.Run(Ort::RunOptions{nullptr}, ort_input_names.data(), ort_inputs.data(),
+                                                    ort_inputs.size(), output_names.data(), output_names.size());
+
+  // Check output type and number of elements.
+  Ort::Value& ort_output = ort_outputs[0];
+  auto output_type_shape = ort_output.GetTensorTypeAndShapeInfo();
+  size_t num_output_elems = output_type_shape.GetElementCount();
+
+  ASSERT_EQ(output_type_shape.GetElementType(), ONNX_TENSOR_ELEMENT_DATA_TYPE_FLOAT);
+  ASSERT_EQ(num_output_elems, 24);
+
+  // Return output data.
+  const float* output_values = ort_output.GetTensorData<float>();
+  output_data.assign(output_values, output_values + num_output_elems);
+}
+
 // Test serializing an OrtGraph (MNIST) to GraphProto. Saves initializers to external file.
 // Checks that the outputs of the serialized and original models are identical.
 TEST(EpGraphTest, SerializeToProto_Mnist) {
@@ -436,6 +469,65 @@ TEST(EpGraphTest, SerializeToProto_ExternalInitializersInMemory) {
   }
 }
 
+// Test serializing an OrtGraph (MNIST) to GraphProto. Saves initializers to external file.
+// Checks that the outputs of the serialized and original models are identical.
+TEST(EpGraphTest, SerializeToProto_ConstantOfShape) {
+  const ORTCHAR_T* original_model_path = ORT_TSTR("testdata/ort_minimal_test_models/tensor_attribute.onnx");
+  const ORTCHAR_T* serialized_model_path = ORT_TSTR("constant_of_shape.onnx");
+  std::filesystem::remove(serialized_model_path);
+
+  {
+    auto test_graph = TestGraph::Load(original_model_path);
+    ASSERT_NE(test_graph, nullptr) << "Failed to load test model";
+
+    // Serialize OrtGraph to GraphProto. Save initializers to external file.
+    std::string ext_ini_file_path = "constant_of_shape_serialized.bin";
+    std::filesystem::remove(ext_ini_file_path);
+    std::ofstream ext_ini_ofs(ext_ini_file_path, std::ios::binary);
+    auto handle_initializer_data = [&ext_ini_ofs, &ext_ini_file_path](const OrtValueInfo* value_info,
+                                                                      const void* data, size_t bytes,
+                                                                      bool& is_external, std::string& location,
+                                                                      int64_t& offset) -> Ort::Status {
+      // OrtValueInfo* could be used to query initializer's name, type, shape,
+      // node consumers, etc.
+      static_cast<void>(value_info);
+
+      if (bytes <= 127) {
+        is_external = false;  // Keep small initializers stored inside the TensorProto.
+        return Ort::Status{nullptr};
+      }
+
+      offset = ext_ini_ofs.tellp();
+      location = ext_ini_file_path;
+      ext_ini_ofs.write(static_cast<const char*>(data), bytes);
+      ext_ini_ofs.flush();
+      is_external = true;  // True if is external initializer.
+
+      return Ort::Status{nullptr};
+    };
+
+    ONNX_NAMESPACE::ModelProto model_proto;
+    ASSERT_CXX_ORTSTATUS_OK(OrtEpUtils::OrtGraphToProto(test_graph->GetOrtGraph(), model_proto,
+                                                        handle_initializer_data));
+
+    std::ofstream ofs(serialized_model_path, std::ios::binary);
+    model_proto.SerializeToOstream(&ofs);
+    ofs.flush();
+
+    ASSERT_TRUE(std::filesystem::exists(serialized_model_path));
+    ASSERT_TRUE(std::filesystem::exists(ext_ini_file_path));
+  }
+
+  // Compare output of the original and serialized models. Should be identical.
+  std::vector<float> output_original;
+  std::vector<float> output_serialized;
+
+  RunConstantOfShapeModel(original_model_path, output_original);
+  RunConstantOfShapeModel(serialized_model_path, output_serialized);
+
+  EXPECT_EQ(output_serialized, output_original);
+}
+
 static void Run3LayerModel(const ORTCHAR_T* model_path, bool input_cond, std::vector<float>& output_data) {
   auto memory_info = Ort::MemoryInfo::CreateCpu(OrtDeviceAllocator, OrtMemTypeCPU);
   Ort::SessionOptions sess_options;
@@ -978,6 +1070,10 @@ static void CheckGraphCApi(const GraphViewer& graph_viewer, const OrtGraph& api_
             ASSERT_EQ(api_node_attr_type, OrtOpAttrType::ORT_OP_ATTR_GRAPH);
             break;
           }
+          case ONNX_NAMESPACE::AttributeProto_AttributeType::AttributeProto_AttributeType_TENSOR: {
+            ASSERT_EQ(api_node_attr_type, OrtOpAttrType::ORT_OP_ATTR_TENSOR);
+            break;
+          }
           default:
             // The unsupported type should be skipped by 'continue' above. It's unexpected so we force test to fail.
             ASSERT_ORTSTATUS_OK(ort_api.CreateStatus(ORT_FAIL, "The attribute type is not in AttributeProto_AttributeType and this case shouldn't be hit."));