This is a list of parliamentary by-elections in the United Kingdom held between 1931 and 1950, with the names of the incumbent and victor and their respective parties.
Where the cause of by-election is given as "resignation" or "seeks re-election", this indicates that the incumbent was appointed on his or her own request to an "office of profit under the Crown", either the Steward of the Chiltern Hundreds or the Steward of the Manor of Northstead.
These appointments are made as a constitutional device for leaving the House of Commons, whose Members are not permitted to resign.
However many independents stood, including some party members who disagreed with the truce.
The Common Wealth Party was formed in part with a view to contesting wartime by-elections.