William John Dyer (1830 – 12 July 1909) was a New Zealand businessman and politician.[1][2][3] Born in London, his family moved to Sydney when he was a child. He ran a trading business between Sydney, New Zealand and the Pacific Islands, and moved to New Zealand in 1857. He lived at different times in Dunedin and Milton and entered politics, contesting a number of elections and representing the Tokomairaro electorate in the provincial council.