John McEwan (1824-1878) was a Mormon pioneer, court clerk, and postmaster in Utah.

John McEwan was born February 24, 1824 in Bonbride, County Down, Ireland, to Henry McEwan and Jane Thompson. He was baptized a member of the Church of Jesus Christ of Latter-Day Saitns in Ireland on November 13, 1840. In 1843, he emigrated to Nauvoo, Illinois, and there met and married Amanda Melvina Higbee on December 23, 1845. They had ten children together. McEwan served as a secretary to Joseph Smith in Nauvoo. He and his family emigrated to Utah in 1848 and were some of the early settlers of Provo. In April 1855, McEwan was called to serve in the Elk Mountain Mission to help establish friendships with the Ute tribes in southeastern Utah and explore the area for settlement. Upon his return from his mission later that year, McEwan was appointed as a district court clerk and moved to work in the Territorial State House in Fillmore, Utah. In May 1858, McEwan volunteered to be a member of the Provo regiment of soldiers called to assist those stationed in Weber Canyon during the Utah War. While in Provo, he also served as president of the 22nd Quorum of Seventies and as postmaster.

John McEwan died on February 27, 1878 in Provo, Utah.