The St Albans by-election of 1919 was a parliamentary by-election held in England in December 1919 for the House of Commons constituency of St Albans in Hertfordshire.
It was the first contested parliamentary election in St Albans since before World War I. Since the previous contest, in 1910, boundaries had been changed and the franchise extended.
The Coalition Unionists (i.e. Conservatives) held the seat, but by only a narrow margin over the Labour Party, even though Labour had existed in the area for less than 12 months, and St Albans had previously been a Conservative safe seat.
The by-election was held to fill the vacancy caused when the 67-year-oldConservative Party Member of Parliament (MP) Sir Hildred Carlile resigned from the House of Commons on 20 November 1919 by the procedural device of accepting appointment as Steward of the Manor of Northstead. Carlile, who had held the seat since the 1906 general election (and was returned unopposed in 1918), cited ill-health as the reason for his departure from politics.
The result at the last General Election in 1918 was;