Herman III, Count of Weimar-Orlamünde (c. 1230 – 1283) was a member of the Weimar-Orlamünde branch of the House of Ascania.
Herman III was a son of Herman II (d. 1247) and his wife, Beatrix of Andechs-Merania (d. 1265). Hermann and his brother Otto III jointly inherited the Franconian possessions of their maternal uncle Otto II. They resided at the Plassenburg.
In 1278, Hermann and Otto divided their inheritace. Otto III took the County of Weimar and the Plassenburg; Hermann III took the County of Orlamünde.
Hermann III died of the plague in 1283.
Marriage and issue
His wife, whose name is unknown, died after 21 July 1279. They had four children:
Elisabeth "the Elder" (d. before 24 March 1333), married:
Hertmann I of Lobdeburg-Arnshaugk (d. 20 February 1289)