Newport by-election may refer to one of three parliamentary by-elections held in the British House of Commons constituency of Newport in Monmouthshire, South Wales:
1922 Newport by-election 1945 Newport by-election 1956 Newport by-election
There is also an upcoming by-election for the modified constituency of Newport West (UK Parliament constituency) in 2019.
See also Newport (Monmouthshire) (UK Parliament constituency) List of United Kingdom by-elections