Leo Sowerby (May 1, 1895–July 7, 1968), American composer and church musician, was the winner of the Pulitzer Prize for music in 1946, and was often called the “Dean of American church music” in the early to mid 20th century.

Sowerby was born in Grand Rapids, Michigan, where he began to compose at the age of ten. Early recognition came when his violin concerto was premiered in 1913 by the Chicago Symphony Orchestra (Stalford & Meckna 2001). In 1921 he was awarded the Rome Prize (from the American Academy in Rome), the first composer to receive this. In addition he received the 1946 Pulitzer Prize for Music for his cantata, the Canticle of the Sun, written in 1944 (Stalford & Meckna 2001).

In 1927 he became organist-choirmaster at St James’s Episcopal Church, Chicago, which was consecrated as a cathedral while he was there (1955). Previously, Sowerby was associate organist at Fourth Presbyterian Church of Chicago (1919).

In 1962, after his retirement from St James’s, he was called to Washington National Cathedral to become the founding director of the College of Church Musicians, a position he held until his death in 1968 (Stalford & Meckna 2001). He died in Port Clinton, Ohio, while at Camp Wa-Li-Ro, in Put-in-Bay, Ohio, the summer choir camp where he had taught for many years.

His substantial output includes over 500 works in every genre but opera and ballet (Stalford & Meckna 2001). His later works, done at St James's, Chicago, and Washington Cathedral, are primarily church music for choir and organ. Sowerby's notable pupils included Robert Beadell, Miriam Clapp Duncan, William Ferris, Edwin Fissinger, Milan Kaderavek, Gail Kubik, Roland Leich, Darwin Leitz, Norman Luboff, Maylon Merrill (Jack Benny's longtime music director), Gerald Near, William Partridge, Florence Price, Ned Rorem, Ronald Stalford, Robert Stewart, and David Van Vactor.