The Selwyn by-election of 1884 was a by-election held on 15 February 1884 during the 8th New Zealand Parliament in the rural Canterbury electorate of Selwyn. The by-election was caused by the death, on 18 December 1883, of the previous MP Edward Lee, who had won the previous by-election in April 1883. The by-election was contested by John McLachlan and Edward Wakefield, the latter winning the show of hands at the nomination meeting. The election was won by Wakefield, with 479 votes to 316.