Willem IV of Horne (1303–1343) was Lord of Altena, Weert, Nederweert, Wessem, Heeze, Leende, and Cortessem. From his niece Beatrice of Leuven he inherited Gaasbeek, Leeuw, Herstal and Montcornet.
- Occupation
- knight
- Citizenship
- Holy Roman Empire
- Born
- 1302, 1295
- Died
- July 22, 1343, August 25, 1343
