William Ajax (1832-1899) was a missionary, translator and editor for Mormon publications in Wales and England, and owned and operated a store and inn in Utah.

William Ajax was born on March 13, 1832, in Llantrisant, Wales, to Thomas Truman Ajax and Rebecka Darcus. However,he was raised by William and Frances Maxwell, whom he considered to be his father and mother, instead of his birth parents. He was briefly educated as a child but eventually became a farm hand from the age of ten to the age of fifteen, abandoning his academic education. He worked for railroads and coal mines until he was twenty-two years old. In November 1853 William joined The Church of Jesus Christ of Latter-day Saints. Soon after his baptism he was called to be a missionary in Wales.

In 1859 William was called to be a translator and editor for the Church's Welsh periodical, "Udgorn Seion." This began a period of self-education for William. He taught himself Greek, Latin, and French while also studying English and other subjects. In March 1861 he moved to Liverpool, England, to work on the "Millennial Star" publication staff. On August 6, 1861, William and Emma Jemima Hughes were married. Together they emigrated to Utah and arrived there on October 5, 1861. Over the years William and Emma had nine children together. In Utah, William ran a general store and operated a successful inn. By 1893, Ajax had stopped considering himself a member of the Church, but he maintained positive feelings about Mormons and religion in general.

William Ajax died on October 2, 1899, in Centre, Utah (also known as Ajax, Utah).