diff --git a/changelog.d/20261013_invalid_gml_polygon.rst b/changelog.d/20261013_invalid_gml_polygon.rst
new file mode 100644
index 00000000..02d89357
--- /dev/null
+++ b/changelog.d/20261013_invalid_gml_polygon.rst
@@ -0,0 +1,5 @@
+Fixed
+-----
+
+*   Ignore invalid numeric coordinates in GML polygon position lists instead
+    of raising ``TypeError``. (#599)
diff --git a/feedparser/namespaces/georss.py b/feedparser/namespaces/georss.py
index c2d9eb09..0b8a604e 100644
--- a/feedparser/namespaces/georss.py
+++ b/feedparser/namespaces/georss.py
@@ -172,6 +172,8 @@ def _parse_poslist(value, geom_type, swap=True, dims=2):
         return _parse_georss_line(value, swap, dims)
     if geom_type == "polygon":
         ring = _parse_georss_line(value, swap, dims)
+        if ring is None:
+            return None
         return {"type": "Polygon", "coordinates": (ring["coordinates"],)}
     return None
 
diff --git a/tests/test_georss.py b/tests/test_georss.py
new file mode 100644
index 00000000..93b7b840
--- /dev/null
+++ b/tests/test_georss.py
@@ -0,0 +1,42 @@
+from __future__ import annotations
+
+import pytest
+
+import feedparser
+from feedparser.namespaces.georss import _parse_poslist
+
+
+@pytest.mark.parametrize("value", [".", "1 invalid", "1 2 3 invalid"])
+def test_invalid_polygon_poslist(value):
+    assert _parse_poslist(value, "polygon") is None
+
+
+@pytest.mark.parametrize("loose", [False, True])
+@pytest.mark.parametrize("value", [".", "1 invalid", "1 2 3 invalid"])
+def test_invalid_gml_polygon_does_not_raise(value, loose, monkeypatch):
+    if loose:
+        monkeypatch.setattr(feedparser.api, "_XML_AVAILABLE", False)
+    data = f"""<feed xmlns="http://www.w3.org/2005/Atom"
+        xmlns:georss="http://www.georss.org/georss"
+        xmlns:gml="http://www.opengis.net/gml">
+        <entry><title>Preserved</title><georss:where><gml:Polygon>
+        <gml:exterior><gml:LinearRing><gml:posList>{value}</gml:posList>
+        </gml:LinearRing></gml:exterior></gml:Polygon></georss:where>
+        </entry></feed>"""
+    result = feedparser.parse(data)
+    assert result.entries[0].title == "Preserved"
+    assert "coordinates" not in result.entries[0].get("where", {})
+
+
+def test_invalid_gml_polygon_minimized_input():
+    result = feedparser.parse(
+        b"<gml:Polygon<gml:LinearRing<gml:posList>.</gml:posList>"
+    )
+    assert result.bozo
+
+
+def test_valid_polygon_poslist():
+    assert _parse_poslist("1 2 3 4 5 6 1 2", "polygon") == {
+        "type": "Polygon",
+        "coordinates": ([(2.0, 1.0), (4.0, 3.0), (6.0, 5.0), (2.0, 1.0)],),
+    }