diff --git a/.github/workflows/python-code-quality.yml b/.github/workflows/python-code-quality.yml
index bc6afaf4bf7..6f5bb7df12e 100644
--- a/.github/workflows/python-code-quality.yml
+++ b/.github/workflows/python-code-quality.yml
@@ -79,6 +79,8 @@ jobs:
           os: ${{ runner.os }}
         env:
           UV_CACHE_DIR: /tmp/.uv-cache
+      - name: Test integration report formatting
+        run: uv run --locked python -m unittest discover -s scripts/integration_test_report/tests
       - name: Run syntax and pyright across packages
         run: uv run poe check-packages
 
diff --git a/python/scripts/integration_test_report/aggregate.py b/python/scripts/integration_test_report/aggregate.py
index 708f47fcf08..6a6e470b8b6 100644
--- a/python/scripts/integration_test_report/aggregate.py
+++ b/python/scripts/integration_test_report/aggregate.py
@@ -478,7 +478,7 @@ def _generate_per_test_table(
     # Sort by module then test name
     for nodeid in sorted(all_tests, key=lambda n: (all_modules.get(n, ""), n)):
         module = all_modules.get(nodeid, "")
-        short = _short_name(nodeid)
+        short = _short_name(nodeid).replace("|", r"\|")
         if provider_filter:
             row = f"| `{short}` | `{module}` |"
         else:
diff --git a/python/scripts/integration_test_report/tests/test_trend_table.py b/python/scripts/integration_test_report/tests/test_trend_table.py
new file mode 100644
index 00000000000..6d4e20d443b
--- /dev/null
+++ b/python/scripts/integration_test_report/tests/test_trend_table.py
@@ -0,0 +1,89 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+"""Regression tests for test names in Markdown trend tables."""
+
+import copy
+import json
+import subprocess
+import sys
+import tempfile
+import unittest
+from pathlib import Path
+from xml.etree import ElementTree
+
+from scripts.integration_test_report.aggregate import generate_trend_report, load_current_run
+
+
+class TrendTableTests(unittest.TestCase):
+    def setUp(self) -> None:
+        self.temp_dir = tempfile.TemporaryDirectory()
+        self.addCleanup(self.temp_dir.cleanup)
+        self.root = Path(self.temp_dir.name)
+
+    def load_run(self, names: list[str], *, dotnet: bool = False) -> dict:
+        reports = self.root / "reports"
+        if dotnet:
+            directory = reports / "dotnet-test-results-net10.0-ubuntu-latest"
+            filename = "results.junit"
+        else:
+            directory = reports / "test-results-openai"
+            filename = "pytest.xml"
+        directory.mkdir(parents=True, exist_ok=True)
+        suite = ElementTree.Element("testsuite", tests=str(len(names)))
+        for name in names:
+            ElementTree.SubElement(suite, "testcase", classname="test_report_input", name=name, time="0")
+        ElementTree.ElementTree(suite).write(directory / filename, encoding="utf-8")
+        return load_current_run(reports)
+
+    def test_python_name_pipe_stays_in_its_cell(self) -> None:
+        report = generate_trend_report([self.load_run(["test_echo[a|b]"])])
+        self.assertIn("| `test_echo[a\\|b]` | `test_report_input` | OpenAI |", report)
+
+    def test_multiple_pipes_stay_in_the_test_name(self) -> None:
+        report = generate_trend_report([self.load_run(["test_echo[a|b|c]"])])
+        self.assertIn("| `test_echo[a\\|b\\|c]` |", report)
+
+    def test_dotnet_name_pipe_stays_in_its_cell(self) -> None:
+        report = generate_trend_report([self.load_run(["TestEcho(a|b)"], dotnet=True)])
+        self.assertIn("| `TestEcho(a\\|b)` | `test_report_input` |", report)
+        self.assertIn("## net10.0 (ubuntu)", report)
+
+    def test_plain_name_and_summary_are_unchanged(self) -> None:
+        run = self.load_run(["test_echo[plain]"])
+        report = generate_trend_report([run])
+        self.assertIn("| `test_echo[plain]` | `test_report_input` | OpenAI |", report)
+        self.assertEqual(run["summary"], {"total": 1, "passed": 1, "failed": 0, "skipped": 0})
+
+    def test_generating_report_does_not_change_history(self) -> None:
+        run = self.load_run(["test_echo[a|b]", "test_echo[plain]"])
+        history = [run, copy.deepcopy(run)]
+        original = copy.deepcopy(history)
+        generate_trend_report(history)
+        self.assertEqual(history, original)
+        self.assertIn("test_report_input::test_echo[a|b]", run["results"])
+        self.assertEqual(run["summary"]["total"], 2)
+        self.assertEqual(run["summary"]["passed"], 2)
+
+    def test_cli_escapes_report_but_preserves_history_keys(self) -> None:
+        self.load_run(["test_echo[a|b]", "test_echo[plain]"])
+        history = self.root / "history.json"
+        output = self.root / "report.md"
+        script = Path(__file__).resolve().parents[1] / "aggregate.py"
+        result = subprocess.run(
+            [sys.executable, "-X", "utf8", "-B", str(script), str(self.root / "reports"), str(history), str(output)],
+            capture_output=True,
+            text=True,
+            encoding="utf-8",
+            check=False,
+        )
+        self.assertEqual(result.returncode, 0, result.stderr)
+        data = json.loads(history.read_text(encoding="utf-8"))["runs"][0]
+        self.assertIn("test_report_input::test_echo[a|b]", data["results"])
+        self.assertEqual(data["summary"]["passed"], 2)
+        report = output.read_text(encoding="utf-8")
+        self.assertIn("| `test_echo[a\\|b]` | `test_report_input` | OpenAI |", report)
+        self.assertIn("| `test_echo[plain]` | `test_report_input` | OpenAI |", report)
+
+
+if __name__ == "__main__":
+    unittest.main()