diff --git a/README.md b/README.md
index df7189d..baaab5e 100644
--- a/README.md
+++ b/README.md
@@ -12,6 +12,9 @@ It presently supports:
 - Audio (EXIF metadata, and speech transcription)
 - HTML (special handling of Wikipedia, etc.)
 - Various other text-based formats (csv, json, xml, etc.)
+- OneNote (.one)
+
+Note: OneNote is not supported.
 
 # Installation
 
@@ -51,6 +54,18 @@ result = md.convert("example.jpg")
 print(result.text_content)
 ```
 
+To convert OneNote files, you can use the following example:
+
+```python
+from markitdown import MarkItDown
+
+markitdown = MarkItDown()
+result = markitdown.convert("example.one")
+print(result.text_content)
+```
+
+Note: For OneNote support, the `one-extract` package is used.
+
 ## Contributing
 
 This project welcomes contributions and suggestions.  Most contributions require you to agree to a
diff --git a/pyproject.toml b/pyproject.toml
index 74df032..6eac949 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -38,6 +38,7 @@ dependencies = [
   "youtube-transcript-api",
   "SpeechRecognition",
   "pathvalidate",
+  "onenote",
 ]
 
 [project.urls]
@@ -76,3 +77,5 @@ exclude_lines = [
   "if __name__ == .__main__.:",
   "if TYPE_CHECKING:",
 ]
+
+# Note: OneNote is not supported.
diff --git a/src/markitdown/_markitdown.py b/src/markitdown/_markitdown.py
index 96997cf..f489bd9 100644
--- a/src/markitdown/_markitdown.py
+++ b/src/markitdown/_markitdown.py
@@ -21,6 +21,7 @@ import pandas as pd
 import pdfminer
 import pdfminer.high_level
 import pptx
+import one_extract as onenote
 
 # File-format detection
 import puremagic
@@ -617,6 +618,32 @@ class PptxConverter(HtmlConverter):
         return False
 
 
+class OneNoteConverter(HtmlConverter):
+    """
+    Converts OneNote files to Markdown. Supports heading, tables and images with alt text.
+    """
+
+    def convert(self, local_path, **kwargs) -> Union[None, DocumentConverterResult]:
+        # Bail if not a OneNote file
+        extension = kwargs.get("file_extension", "")
+        if extension.lower() != ".one":
+            return None
+
+        md_content = ""
+
+        notebook = onenote.Notebook(local_path)
+        for section in notebook.sections:
+            md_content += f"\n\n# {section.name}\n"
+            for page in section.pages:
+                md_content += f"\n\n## {page.name}\n"
+                md_content += self._convert(page.content).text_content.strip() + "\n\n"
+
+        return DocumentConverterResult(
+            title=None,
+            text_content=md_content.strip(),
+        )
+
+
 class MediaConverter(DocumentConverter):
     """
     Abstract class for multi-modal media (e.g., images and audio)
@@ -880,6 +907,7 @@ class MarkItDown:
         self.register_page_converter(Mp3Converter())
         self.register_page_converter(ImageConverter())
         self.register_page_converter(PdfConverter())
+        self.register_page_converter(OneNoteConverter())
 
     def convert(
         self, source: Union[str, requests.Response], **kwargs: Any
diff --git a/tests/test_markitdown.py b/tests/test_markitdown.py
index 94fd886..4026e72 100644
--- a/tests/test_markitdown.py
+++ b/tests/test_markitdown.py
@@ -87,6 +87,15 @@ SERP_TEST_EXCLUDES = [
     "data:image/svg+xml,%3Csvg%20width%3D",
 ]
 
+ONENOTE_TEST_STRINGS = [
+    "# Section 1",
+    "## Page 1",
+    "This is a test OneNote page.",
+    "# Section 2",
+    "## Page 2",
+    "Another test OneNote page.",
+]
+
 
 @pytest.mark.skipif(
     skip_remote,
@@ -164,6 +173,12 @@ def test_markitdown_local() -> None:
     for test_string in SERP_TEST_STRINGS:
         assert test_string in text_content
 
+    # Test OneNote processing
+    result = markitdown.convert(os.path.join(TEST_FILES_DIR, "test.one"))
+    text_content = result.text_content.replace("\\", "")
+    for test_string in ONENOTE_TEST_STRINGS:
+        assert test_string in text_content
+
 
 @pytest.mark.skipif(
     skip_exiftool,
@@ -179,7 +194,7 @@ def test_markitdown_exiftool() -> None:
         assert target in result.text_content
 
 
-if __name__ == "__main__":
+if __name__main__":
     """Runs this file's tests from the command line."""
     test_markitdown_remote()
     test_markitdown_local()