The Brooklyn by-election 1951 was a by-election held in the Brooklyn electorate in Wellington during the 29th New Zealand Parliament, on 17 February 1951.

The 29th New Zealand Parliament was a term of the Parliament of New Zealand. It opened in 1950, following the 1949 general election. It was dissolved in 1951 in preparation for the 1951 general election. The governing Labour Party had been defeated in the election by the National Party. This marked the end of the First Labour government and the beginning of the First National government.