Frederick Lucian Hosmer (1840–1929) was an American Unitarian minister who served congregations in Massachusetts, Illinois, Ohio, Missouri, and California and who wrote many significant hymns. Beginning in 1875 and continuing for nearly four decades, he and William Channing Gannett worked together, making a contribution to hymnody comparable to that of the "two Sams," Longfellow and Johnson, a generation earlier.