The Raglan by-election of 1927 was a by-election held in the Raglan electorate during the 22nd New Zealand Parliament, on 29 September 1927. It was caused by the death of incumbent MP Richard Bollard of the Reform Party. Despite being a local contest it quickly became a national contest in miniature due to growing discontent with the Reform Government.

Joseph Gordon Coates served as the 21st prime minister of New Zealand from 1925 to 1928. He was the third successive Reform prime minister since 1912.