The Torrington by-election of 1958, in Devon, England, was the first gain by the British Liberal Party at a by-election since Holland with Boston in 1929.
The election was caused by the accession of George Lambert, National Liberal and Conservative Member of Parliament for Torrington to a hereditary peerage as Viscount Lambert. He had held the constituency since its creation in 1950, with large majorities over Labour Party candidates. The Liberal Party had only contested the seat in 1950, although they then came second, with 25% of the vote. Lambert's father, also George Lambert, had held the predecessor seat of South Molton for much of its history, initially as a Liberal, but then as a National Liberal.
Although generally popular, the Conservative administration of Harold Macmillan had been hit by differences over economic policy, and in January 1958, all the Government's Treasury Ministers had resigned.
The Liberal Party had reached its lowest ebb in the 1951 general election, winning just 2.5% of the vote nationally, and gaining only six MPs. They had been reduced to five seats when they lost the Carmarthen by-election, 1957, but their fortunes had shown signs of a revival when they came a close second in North Dorset later in the year, and Rochdale early in 1958.