diff --git a/flink-models/flink-model-triton/src/main/java/org/apache/flink/model/triton/TritonInferenceModelFunction.java b/flink-models/flink-model-triton/src/main/java/org/apache/flink/model/triton/TritonInferenceModelFunction.java
index 46bd0e0a96cbb1..4e4e7f655ccad0 100644
--- a/flink-models/flink-model-triton/src/main/java/org/apache/flink/model/triton/TritonInferenceModelFunction.java
+++ b/flink-models/flink-model-triton/src/main/java/org/apache/flink/model/triton/TritonInferenceModelFunction.java
@@ -963,7 +963,7 @@ private String buildInferenceRequest(RowData rowData) throws JsonProcessingExcep
         // Add inputs
         ArrayNode inputsArray = objectMapper.createArrayNode();
         ObjectNode inputNode = objectMapper.createObjectNode();
-        inputNode.put("name", inputName.toUpperCase());
+        inputNode.put("name", inputName);
 
         // Map Flink type to Triton type
         TritonDataType tritonType = TritonTypeMapper.toTritonDataType(inputType);
@@ -997,7 +997,7 @@ private String buildInferenceRequest(RowData rowData) throws JsonProcessingExcep
         // Add outputs (request all outputs)
         ArrayNode outputsArray = objectMapper.createArrayNode();
         ObjectNode outputNode = objectMapper.createObjectNode();
-        outputNode.put("name", outputName.toUpperCase());
+        outputNode.put("name", outputName);
         outputsArray.add(outputNode);
         requestNode.set("outputs", outputsArray);
 
diff --git a/flink-models/flink-model-triton/src/test/java/org/apache/flink/model/triton/TritonTensorNameCasingTest.java b/flink-models/flink-model-triton/src/test/java/org/apache/flink/model/triton/TritonTensorNameCasingTest.java
new file mode 100644
index 00000000000000..aaa797f9050e9b
--- /dev/null
+++ b/flink-models/flink-model-triton/src/test/java/org/apache/flink/model/triton/TritonTensorNameCasingTest.java
@@ -0,0 +1,209 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.flink.model.triton;
+
+import org.apache.flink.configuration.Configuration;
+import org.apache.flink.configuration.ReadableConfig;
+import org.apache.flink.table.api.DataTypes;
+import org.apache.flink.table.api.Schema;
+import org.apache.flink.table.catalog.CatalogModel;
+import org.apache.flink.table.catalog.Column;
+import org.apache.flink.table.catalog.ObjectIdentifier;
+import org.apache.flink.table.catalog.ResolvedCatalogModel;
+import org.apache.flink.table.catalog.ResolvedSchema;
+import org.apache.flink.table.data.GenericRowData;
+import org.apache.flink.table.data.binary.BinaryStringData;
+import org.apache.flink.table.factories.ModelProviderFactory;
+import org.apache.flink.table.functions.FunctionContext;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import okhttp3.mockwebserver.MockResponse;
+import okhttp3.mockwebserver.MockWebServer;
+import okhttp3.mockwebserver.RecordedRequest;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.util.Collections;
+import java.util.concurrent.TimeUnit;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests that tensor names in Triton inference requests preserve the original column name casing
+ * (i.e., are not unconditionally uppercased).
+ *
+ * <p>Triton's KServe V2 protocol treats tensor names as case-sensitive. A model configured with
+ * {@code input} and {@code output} tensors in its {@code config.pbtxt} will reject requests that
+ * send {@code INPUT} and {@code OUTPUT}. This test verifies the fix for that bug.
+ */
+class TritonTensorNameCasingTest {
+
+    private static final ObjectMapper MAPPER = new ObjectMapper();
+
+    private MockWebServer mockServer;
+
+    @BeforeEach
+    void setUp() throws IOException {
+        mockServer = new MockWebServer();
+        mockServer.start();
+    }
+
+    @AfterEach
+    void tearDown() throws IOException {
+        mockServer.shutdown();
+    }
+
+    private String baseUrl() {
+        return mockServer.url("/").toString().replaceAll("/$", "");
+    }
+
+    /**
+     * Verifies that lowercase column names declared in the model schema are sent to Triton as-is,
+     * not converted to uppercase.
+     *
+     * <p>Before the fix, {@code buildInferenceRequest} called {@code inputName.toUpperCase()} and
+     * {@code outputName.toUpperCase()}, causing HTTP 400 responses from any model whose {@code
+     * config.pbtxt} declared lowercase tensor names.
+     */
+    @Test
+    void testLowercaseTensorNamesArePreserved() throws Exception {
+        String tritonResponse =
+                "{\"outputs\":[{\"name\":\"output\",\"datatype\":\"FP32\","
+                        + "\"shape\":[3],\"data\":[0.1,0.2,0.3]}]}";
+        mockServer.enqueue(
+                new MockResponse()
+                        .setResponseCode(200)
+                        .setBody(tritonResponse)
+                        .setHeader("Content-Type", "application/json"));
+
+        TritonInferenceModelFunction function = buildFunction("input", "output");
+        function.open(new FunctionContext(null, null, null));
+        try {
+            GenericRowData row = GenericRowData.of(BinaryStringData.fromString("hello world"));
+            function.asyncPredict(row).get(5, TimeUnit.SECONDS);
+        } finally {
+            function.close();
+        }
+
+        RecordedRequest captured = mockServer.takeRequest(5, TimeUnit.SECONDS);
+        assertThat(captured).isNotNull();
+
+        JsonNode body = MAPPER.readTree(captured.getBody().readUtf8());
+        assertThat(body.get("inputs").get(0).get("name").asText())
+                .as("input tensor name must not be uppercased")
+                .isEqualTo("input");
+        assertThat(body.get("outputs").get(0).get("name").asText())
+                .as("output tensor name must not be uppercased")
+                .isEqualTo("output");
+    }
+
+    /**
+     * Verifies that mixed-case column names are also sent without modification.
+     *
+     * <p>The fix removes the unconditional {@code toUpperCase()} call, so any casing — not just
+     * all-lowercase — must now round-trip correctly.
+     */
+    @Test
+    void testMixedCaseTensorNamesArePreserved() throws Exception {
+        String tritonResponse =
+                "{\"outputs\":[{\"name\":\"myOutput\",\"datatype\":\"FP32\","
+                        + "\"shape\":[1],\"data\":[0.5]}]}";
+        mockServer.enqueue(
+                new MockResponse()
+                        .setResponseCode(200)
+                        .setBody(tritonResponse)
+                        .setHeader("Content-Type", "application/json"));
+
+        TritonInferenceModelFunction function = buildFunction("myInput", "myOutput");
+        function.open(new FunctionContext(null, null, null));
+        try {
+            GenericRowData row = GenericRowData.of(BinaryStringData.fromString("test"));
+            function.asyncPredict(row).get(5, TimeUnit.SECONDS);
+        } finally {
+            function.close();
+        }
+
+        RecordedRequest captured = mockServer.takeRequest(5, TimeUnit.SECONDS);
+        assertThat(captured).isNotNull();
+
+        JsonNode body = MAPPER.readTree(captured.getBody().readUtf8());
+        assertThat(body.get("inputs").get(0).get("name").asText())
+                .as("mixed-case input tensor name must not be uppercased")
+                .isEqualTo("myInput");
+        assertThat(body.get("outputs").get(0).get("name").asText())
+                .as("mixed-case output tensor name must not be uppercased")
+                .isEqualTo("myOutput");
+    }
+
+    private TritonInferenceModelFunction buildFunction(String inputColName, String outputColName) {
+        Configuration config = new Configuration();
+        config.setString(TritonOptions.ENDPOINT.key(), baseUrl());
+        config.setString(TritonOptions.MODEL_NAME.key(), "test-model");
+        config.setString(TritonOptions.MODEL_VERSION.key(), "1");
+
+        CatalogModel origin =
+                CatalogModel.of(
+                        Schema.newBuilder().column(inputColName, "STRING").build(),
+                        Schema.newBuilder().column(outputColName, "ARRAY<FLOAT>").build(),
+                        Collections.emptyMap(),
+                        null);
+
+        ResolvedSchema inputSchema =
+                ResolvedSchema.of(Column.physical(inputColName, DataTypes.STRING()));
+        ResolvedSchema outputSchema =
+                ResolvedSchema.of(
+                        Column.physical(outputColName, DataTypes.ARRAY(DataTypes.FLOAT())));
+
+        ResolvedCatalogModel resolvedModel =
+                ResolvedCatalogModel.of(origin, inputSchema, outputSchema);
+
+        ModelProviderFactory.Context factoryContext =
+                new ModelProviderFactory.Context() {
+                    @Override
+                    public ObjectIdentifier getObjectIdentifier() {
+                        return ObjectIdentifier.of("default", "default", "test_model");
+                    }
+
+                    @Override
+                    public ResolvedCatalogModel getCatalogModel() {
+                        return resolvedModel;
+                    }
+
+                    @Override
+                    public ReadableConfig getConfiguration() {
+                        return config;
+                    }
+
+                    @Override
+                    public ClassLoader getClassLoader() {
+                        return Thread.currentThread().getContextClassLoader();
+                    }
+
+                    @Override
+                    public boolean isTemporary() {
+                        return true;
+                    }
+                };
+
+        return new TritonInferenceModelFunction(factoryContext, config);
+    }
+}