| Ignaz von Rudhart | |
| Office: | Prime Minister of Greece |
| Term Start: | 2 February |
| Term End: | 8 December 1837 (o.s.) |
| Predecessor: | Graf von Armansperg |
| Successor: | Otto |
| Birth Date: | 11 March 1790 |
| Birth Place: | Weismain, Upper Franconia |
| Death Place: | Trieste, Austrian Empire |
Ignaz Ritter von Rudhart (11 March 1790 in Weismain, Upper Franconia - 11 May 1838) was a Bavarian scholar and public servant who was dispatched to Greece to serve as President of the Privy Council (Prime Minister) during the reign of King Otto.
Von Rudhart had received a doctorate of law from the University of Munich, had authored two books, one of them a statistical survey of the Bavarian Kingdom, which he served as a member of the Council of State, prior to his appointment as Prime Minister of Greece.
When he arrived in Athens in February 1837, he was received suspiciously by the English legate Lyons (who had been a supporter of his predecessor, von Armansperg) and immediately found himself at odds with the king over the role of the prime minister. King Otto was committed to an absolute monarchy and was resistant to a powerful chief minister. Von Rudhart had a series of clashes with king, and being disliked by Queen Amalia, his resignation was accepted by King Otto 10 months after he arrived in Greece. Otto served as his own President of the Privy Council until a constitution was forced on him during the 3 September 1843 Revolution.