The 1948 Wigan by-election of 4 March 1948 was held after the death of the incumbent Labour MP, William Foster.
The by-election was contested by four candidates: Ronald Williams (Labour), Harold Dowling (Conservative), Thomas Rowlandson (Communist), and Owen L Roberts (King's Cavalier). Roberts was an ex-RAF Pathfinder observer fighting the election "for the peace and prosperity of the country."[1]
The result was a hold for the Labour Party, with Williams gaining 59.1% of the vote, in spite of a 6.5% swing to the Conservative Party.