The first meeting of St. Thomas parishioners was held October 1, 1940 in the Spartan Room of the Union Building on the campus of Michigan Agricultural College. Rev. Cecil Winters celebrated the first Mass in the State Theatre on Abbot Road.
Fr. Jerome MacEachin was appointed to St. Thomas Aquinas in May, 1943. Fr. Mac, as he was fondly known, saw the need to expand the parish. In 1948 property was purchased on Alton Road. A school was opened in September 1949 with ninety-five students in six grades. Fr. Mac oversaw the building of a convent, school additions including a gym that served as the temporary church, the present church and the rectory.