Sydney, an electoral district of the Legislative Assembly in the Australian state of New South Wales, has had two incarnations, the first from 1920 to 1927 as a five-member electorate, the second from 2007 to the present as a single-member electorate.
John Birt died on 21 June 1925. Between 1920 and 1927 the Legislative Assembly was elected using a form of proportional representation with multi-member seats and a single transferable vote (modified Hare-Clark). The Parliamentary Elections (Casual Vacancies) Act, provided that casual vacancies were filled by the next unsuccessful candidate on the incumbent member's party list. Patrick Minahan had the most votes of the unsuccessful candidates at the 1925 election and took his seat on 24 June 1925.