Arfon by election, 1915

The Arfon by-election, 1915 was a parliamentary by-election held on 6 July 1915 for the Arfon division of Caernarvonshire in North Wales, a constituency of the British House of Commons.

The by-election was caused by death at the age of 55 of the Liberal Member of Parliament (MP) William Jones, a Junior Lord of the Treasury in H. H. Asquith's Liberal government, who had held the seat since the 1895 general election.

The only candidate nominated to contest the by-election was the Liberal Caradoc Rees, who was therefore elected unopposed. Rees held the seat until the constituency was abolished at the general election in December 1918.