William Otto of Nassau-Siegen | |
|---|---|
 Count William Otto of Nassau-Siegen. Detail from a painting attributed to Wybrand de Geest, 1635–1640. Foundation Historical Collections of the House of Orange-Nassau, The Hague. | |
| Coat of arms |  |
| Full name | William Otto Count of Nassau-Siegen |
| Native name | Wilhelm Otto Graf von Nassau-Siegen |
| Born | Wilhelm Otto Graf zu Nassau, Katzenelnbogen, Vianden und Diez, Herr zu Beilstein 23 June 1607 Dillenburg Castle |
| Died | 14 August 1641 (aged 34) near Wolfenbüttel |
| Buried | 16 September 1641 Kassel |
| Noble family | House of Nassau-Siegen |
| Spouse(s) | – |
| Issue | – |
| Father | John VII 'the Middle' of Nassau-Siegen |
| Mother | Margaret of Schleswig-Holstein-Sonderburg |
| Occupation | Officer in the Swedish Army |
Count William Otto of Nassau-Siegen (23 June 1607 – 14 August 1641), German: Wilhelm Otto Graf von Nassau-Siegen, official titles: Graf zu Nassau, Katzenelnbogen, Vianden und Diez, Herr zu Beilstein, was a count from the House of Nassau-Siegen, a cadet branch of the Ottonian Line of the House of Nassau. He served as an officer in the Swedish Army.