In 1878, four religious sisters from the convent of St. Benedict in St. Joseph, Minnesota, arrived in Bismarck to staff what was then the St. Mary's Academy and Boarding School.

[4] SMCHS currently sponsors 24 varsity sports with 12 of them being co-ops with surrounding Bismarck and Mandan high schools.

SMCHS is a member of the North Dakota High School Activities Association (NDHSAA) and the Western Dakota Association (WDA) SMCHS has 7 different competitive activities which students can participate in under the NDHSAA.

Along with these activities SMCHS also offers Jazz Band, Steel Drum Band, Jazz Choir, Science Olympiad, Knights of Virtue, Leo Lions, SM Messenger, Vera Forma, Assistant Chaplains, Science Club, Robotics Club, Student Council, Art Club, Catholic Athletes for Christ, National Honor Society, Future Business Leaders of America (FBLA), and many others.

Students are given the rare opportunity to perform music on steelpan instruments which trace their origins to Trinidad and Tobago and the Caribbean.