Siegfried III, Count of Weimar-Orlamünde

Siegfried III, Count of Weimar-Orlamünde (c. 1155 – 1206) was a member of the House of Ascania and a ruling Count of Weimar-Orlamünde.

He was the son of Count Herman I and his wife Irmgard. Herman I was son of Albert the Bear Count of Anhalt, Margrave of Brandenburg and Duke of Saxony.

He was regarded as a supporter of the House of Hohenstaufen. He spent some time in Denmark. He married Sophie (1159 – c. 1208), a daughter of King Valdemar I of Denmark and had two sons:
 * Albert II
 * Herman II