William James Barratt (25 January 1823 – 10 September 1889) was an English convert to Mormonism and became the first Latter Day Saint to live in Australia when he was sent there as a missionary of the Church of Jesus Christ of Latter Day Saints. However, he ultimately apostatized from Mormonism. Barratt became a prominent land owner in the Bald Hills and Inman Valley areas of South Australia. He married Ann Gibson and fathered seven children. Barratt died at Bald Hills, South Australia and is buried at Victor Harbor, South Australia.