The King's County Tullamore by-election of 1918 was held on 19 April 1918. The by-election was held due to the death of the incumbent Irish Parliamentary MP, Edward John Graham. It was won by the Sinn Féin candidate Patrick McCartan, who stood unopposed.
McCartan had previously contested the by-election in South Armagh for Sinn Féin but lost out to the Irish Parliamentary Party candidate. He was subsequently elected for the merged King's County constituency in the 1918 general election,
References
Tullamore by-election, 1918 Wikipedia(Text) CC BY-SA