Alexander Cairns (23 April 1850 – 16 June 1936) was a New Zealand cricketer. He played three first-class matches for Otago between the 1867–68 and 1870–71 seasons. All three matches he played in were against Canterbury and were the only first-class matches played in New Zealand during these seasons, although Cairns did not play in the 1869–70 season's match between the two sides. He scored a total of 39 runs and took eight wickets.