John Stradling Thomas Conservative Huw Edwards Labour The 1991 Monmouth by-election was a by-election held for the British House of Commons constituency of Monmouth in Wales on 16 May 1991.
It was won by the Labour Party candidate Huw Edwards.
The seat had become vacant when the sitting Conservative Member of Parliament (MP), Sir John Stradling Thomas had died at the age of 65 on 29 March 1991.
The result was a victory for the Labour candidate, Huw Edwards, who took the seat on a swing of 12.6%.
However, he was unseated at the 1992 general election by his defeated Conservative opponent Roger Evans, who held the seat until Edwards regained it in the Labour landslide at the 1997 general election.