The April 1865 Bruce by-election was a New Zealand by-election held in the multi-member electorate of Bruce during the 3rd New Zealand Parliament on 8 April 1865. It was triggered on 9 January that year by the resignation of separationist Thomas Gillies and won by prominent settler Arthur John Burns. The more liberal businessman William John Dyer was the sole other contester of the by-election, finishing with 43.33% of the vote.