List of United Kingdom by-elections (1900–1918)

This is a list of parliamentary by-elections in the United Kingdom held between 1900 and 1918, with the names of the incumbent and victor and their respective parties. Where a political party gained a seat at the election, the result is highlighted: pink for Labour (including Labour Representation Committee), light blue for Conservative (including Liberal Unionist, Irish Unionist and Scottish Unionist), orange for Liberal (including Liberal-Labour), green for Sinn Féin, light green for the Irish Parliamentary Party and grey for any other gain.