The 1939 Fareham by-election was a parliamentary by-election held for the British House of Commons constituency of Fareham in Hampshire on 6 October 1939.
The seat had become vacant when Sir Thomas Inskip, the constituency's Conservative Party Member of Parliament had been ennobled as Viscount Caldecote on 6 September and appointed as Lord Chancellor.
The Conservative candidate, Dymoke White, was returned unopposed.
During World War II, unopposed by-elections were common, since the major parties had agreed not to contest by-elections when vacancies arose in seats held by the other parties; contests occurred only when independent candidates or minor parties chose to stand, and the Common Wealth Party was formed in 1942 with the specific aim of contesting war-time by-elections.
However, this was the first by-election since the start of the war, and no other candidates were nominated.