The 1875 City of Auckland West by-elections were two by-elections held in the City of Auckland West electorate in Auckland, following two resignations during the 4th New Zealand Parliament * Thomas Gillies resigned when he was appointed a judge of the Supreme Court and was replaced unopposed on 27 March by George Grey. * John Williamson died on 16 February and was replaced on 14 April by Patrick Dignan. He was opposed by Joseph Dargaville, a member of the Orange Order, Dignan was a Catholic.