The University of Saint Mary (USM) is a private liberal arts university in Leavenworth, Kansas, United States. It is sponsored by the Sisters of Charity of Leavenworth, who established it as Saint Mary College. Though it was originally a school for women, the school is now coeducational. The mother house of the order is also on the premises. At one time the nuns' property had its own post office, Xavier, Kansas, the name honoring St. Francis Xavier.