The West Derbyshire by-election of 1944 was held on 17 February 1944. The byelection was held due to the resignation of the incumbent Conservative MP, Henry Hunloke. Hunloke was the brother-in-law of Edward Cavendish, 10th Duke of Devonshire, who had held the seat from 1923 until 1938, when he succeeded to his title and was replaced by Hunloke. The seat had been held previously by Hunloke's father-in-law (1891-1908, before becoming the 9th Duke), and by the 9th Duke's brother-in-law, the future 6th Marquess of Lansdowne (1908-1918).
This control by the Cavendish family had been interrupted in 1918-1923 by Charles Frederick White, who was elected as a Liberal. White died in 1923. His son, also Charles Frederick White, had stood for the seat in the 1938 by-election as a Labour candidate, but lost to Hunloke by 5,500 votes.
The resignation of Hunloke was due to the imminent collapse of his marriage (he was divorced from his Cavendish wife the next year and remarried immediately). The Conservative Party then selected William Cavendish, the 10th Duke's eldest son, as their candidate.
The major parties had formed a national unity government during World War II and agreed that no by-elections would be contested during the war. In contravention of this agreement, Charles Frederick White stood in the by-election as an Independent Labour candidate.
In an acrimonious campaign, White pressed for social change, securing the support of local Labour activists. White won, defeating Cavendish by over 4,000 votes, a swing of 9,000 from 1938.
Once in Parliament, White took the official Labour whip.