diff --git a/tensorrt_llm/quantization/quantize_by_modelopt.py b/tensorrt_llm/quantization/quantize_by_modelopt.py
index 17cf57dd1dc3..9c23dd805f00 100755
--- a/tensorrt_llm/quantization/quantize_by_modelopt.py
+++ b/tensorrt_llm/quantization/quantize_by_modelopt.py
@@ -500,6 +500,17 @@ def get_model_type(model):
     return None
 
 
+def _is_cnn_dailymail_local_repo(path: str) -> bool:
+    if not os.path.isdir(path):
+        return False
+    # The loader only uses the "3.0.0" config.
+    if os.path.isdir(os.path.join(path, "3.0.0")):
+        return True
+    if os.path.isfile(os.path.join(path, "cnn_dailymail.py")):
+        return True
+    return False
+
+
 def get_calib_dataloader(dataset_name_or_dir="cnn_dailymail",
                          tokenizer=None,
                          batch_size=1,
@@ -526,7 +537,8 @@ def get_calib_dataloader(dataset_name_or_dir="cnn_dailymail",
                                    split="train",
                                    trust_remote_code=True)
         dataset = dataset.select(range(calib_size))
-    elif "cnn_dailymail" in dataset_name_or_dir:
+    elif "cnn_dailymail" in dataset_name_or_dir or _is_cnn_dailymail_local_repo(
+            dataset_name_or_dir):
         dataset = load_dataset(
             dataset_name_or_dir,
             name="3.0.0",
@@ -1140,7 +1152,8 @@ def get_nemo_calib_dataloader(dataset_name_or_dir="cnn_dailymail",
                                split="train",
                                trust_remote_code=True)
         text_column = "text"
-    elif "cnn_dailymail" in dataset_name_or_dir:
+    elif "cnn_dailymail" in dataset_name_or_dir or _is_cnn_dailymail_local_repo(
+            dataset_name_or_dir):
         dataset = load_dataset(dataset_name_or_dir,
                                name="3.0.0",
                                split="train",
diff --git a/tests/unittest/others/test_quantize_calib_dataset.py b/tests/unittest/others/test_quantize_calib_dataset.py
new file mode 100644
index 000000000000..7a2e0549baf4
--- /dev/null
+++ b/tests/unittest/others/test_quantize_calib_dataset.py
@@ -0,0 +1,83 @@
+# SPDX-FileCopyrightText: Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed 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.
+import os
+import tempfile
+
+import torch
+from utils.util import skip_no_modelopt
+
+
+@skip_no_modelopt
+def test_is_cnn_dailymail_local_repo():
+    from tensorrt_llm.quantization.quantize_by_modelopt import _is_cnn_dailymail_local_repo
+
+    # Non-existent path
+    assert not _is_cnn_dailymail_local_repo("/does/not/exist")
+
+    # Empty directory
+    with tempfile.TemporaryDirectory() as d:
+        assert not _is_cnn_dailymail_local_repo(d)
+
+    # 3.0.0 subdir
+    with tempfile.TemporaryDirectory() as d:
+        os.makedirs(os.path.join(d, "3.0.0"))
+        assert _is_cnn_dailymail_local_repo(d)
+
+    # Other versions not detected
+    for version in ("1.0.0", "2.0.0"):
+        with tempfile.TemporaryDirectory() as d:
+            os.makedirs(os.path.join(d, version))
+            assert not _is_cnn_dailymail_local_repo(d), (
+                f"version subdir {version} should not be detected"
+            )
+
+    # Directory with the cnn_dailymail.py builder script
+    with tempfile.TemporaryDirectory() as d:
+        open(os.path.join(d, "cnn_dailymail.py"), "w").close()
+        assert _is_cnn_dailymail_local_repo(d)
+
+    # Directory with unrelated content
+    with tempfile.TemporaryDirectory() as d:
+        os.makedirs(os.path.join(d, "train"))
+        open(os.path.join(d, "data.parquet"), "w").close()
+        assert not _is_cnn_dailymail_local_repo(d)
+
+
+@skip_no_modelopt
+def test_get_calib_dataloader_local_cnn_dailymail(monkeypatch):
+    from tensorrt_llm.quantization import quantize_by_modelopt
+
+    captured = {}
+
+    def fake_load_dataset(path, **kwargs):
+        captured["kwargs"] = kwargs
+        return {"article": ["calibration article"] * 2}
+
+    def fake_tokenizer(dataset, **kwargs):
+        return {"input_ids": torch.ones(len(dataset), 4, dtype=torch.long)}
+
+    monkeypatch.setattr(quantize_by_modelopt, "load_dataset", fake_load_dataset)
+
+    with tempfile.TemporaryDirectory() as d:
+        # Name lacks "cnn_dailymail".
+        os.makedirs(os.path.join(d, "3.0.0"))
+        dataloader = quantize_by_modelopt.get_calib_dataloader(
+            dataset_name_or_dir=d,
+            tokenizer=fake_tokenizer,
+            calib_size=2,
+        )
+
+    assert captured["kwargs"].get("name") == "3.0.0"
+    assert len(list(dataloader)) == 2