George Augustus Frederick FitzClarence, 1st Earl of Munster GCH PC FRS FRAS (29 January 1794 – 20 March 1842), was an English peer and soldier.

The eldest illegitimate son of William IV of the United Kingdom and his long-time mistress Dorothea Jordan, he was well-educated, although his written English was poor (as was that of several of his royal uncles).

George, like his siblings, was dissatisfied with the provisions made for him and this, combined with his increasing mental instability, caused a series of quarrels with his father, which ended in a complete breach in relations between them.

[4] The estrangement caused the King great distress, but those close to him thought it better that there be as little contact as possible, since Munster's visits invariably upset his father.

"[10] At his inquest, his doctor and a surgeon told the coroner that they believed he was going mad, and in recent years there has been speculation that he suffered from the probably hereditary malady of porphyria which may have afflicted his grandfather and several other members of the family.