Mathias Clement Lenihan, (October 6, 1854 – August 19, 1943) was a 20th-century archbishop in the Catholic Church in the United States.

[1] He was ordained a Catholic priest on December 20, 1879 by Bishop John Hennessy for the Diocese of Dubuque.

The co-consecrators were Bishops James John Keane of Cheyenne and Joseph Bernard Cotter, of Winona.

He was involved in temperance reform, building the parochial school system in the diocese, and constructing a new cathedral.

[3] Pope Pius XI accepted his resignation as bishop of Great Falls on January 18, 1930.