Mary S. Cummins (née, Slemons; 1854–1894) was a 19th-century American educator who was also the leader of various religious, social reform, and teachers' organizations.

Ambitious to go beyond the academic course, she pushed her way, by her own efforts, to graduating with a full diploma from the Augusta Female Seminary (now, Mary Baldwin University), Staunton, Virginia.

She also served as president of the Synodical Missionary Society and a State member of the executive board of Home Missions of New York for the Presbyterian Church.

They settled in Helena, where Mr. Cummins became engaged in the real estate business, both on his own account and for others, and also had interests in various mining enterprises.

[1] Cummins, together with Prof. Joseph C. Templeton, also a professor in Montana Wesleyan, handled the inside management of university affairs.

Partly as a result of that tour, the banner presented by Willard for the largest percentage of gain in membership in the Western States was given to Montana in 1891.