The 1905 Australasian Championships was a tennis tournament played on Grass courts in Melbourne, Australia at Warehouseman's Cricket Ground. The tournament took place from 17 November through 27 November 1905. It was the inaugural edition of the Australasian Championships and consisted of a men's singles and men's doubles competition. The men's singles event had a field of 17 players and was won by Australian Rodney Heath.
Rodney Heath defeated Arthur Curtis, 4–6, 6–3, 6–4, 6–4 
Randolph Lycett / Tom Tachell defeated E.T. Barnard / B. Spence, 11–9, 8–6, 1–6, 4–6, 6–1