The Newport by-election, 1945 was a parliamentary by-election held on 17 May 1945 for the British House of Commons constituency of Newport in Monmouthshire. It was the last by-election of the 1935-1945 Parliament.
The seat had become vacant on the death of the constituency's Conservative Member of Parliament (MP), Sir Reginald Clarry, on 17 January 1945, aged 62. He had held the seat since a 1922 by-election, with a two-year gap after his defeat at the 1929 general election (he was re-elected at the 1931 election).
The Conservative Party selected as its candidate Ronald Bell, an Oxford-educated barrister who had been heavily defeated at the Caerphilly by-election in 1939. In keeping with a war-time electoral pact, the Labour and Liberal parties did not field candidates, and Bell's only opponent was Robert Edwards, the Chairman of the Independent Labour Party (ILP).