1 Not an election, but the date of a party change. The Irish Parliamentary Party had been created in 1882, on the initiative of Charles Stewart Parnell's Irish National League. Both the IPP and the INL split into Parnellite and Anti-Parnellite factions, in December 1890. The Parnellites remained members of the Irish National League after the split and the Anti-Parnellites organised the Irish National Federation in March 1891. The two organisations and the United Irish League merged in 1900, to re-create the Irish Parliamentary Party.
2 Date of polling day. The result was declared on 28 December 1918, to allow time for votes cast by members of the armed forces to be included in the count.