The Mangere by-election of 1977 was a by-election for the electorate of Mangere on 26 March 1977 during the 38th New Zealand Parliament. The by-election resulted from the resignation of the previous member Colin Moyle after accusations against him in parliament, and he was replaced by David Lange, also of the Labour Party. Apart from Lange, there were seven other candidates in the by-election.

The 38th New Zealand Parliament was a term of the New Zealand Parliament. It was elected at the 1975 general election on 29 November of that year.