Ralph Fletcher Seymour (March 18, 1876 – January 1, 1966) was an American artist, author, and publisher of the late nineteenth and the twentieth centuries.

[3] Seymour illustrated or designed a range of books, often in high-quality limited editions, including Elizabeth Barrett Browning's Sonnets from the Portuguese (1899), John Keats's The Eve of St. Agnes (1900), John Milton's Ode on the Morning of Christ's Nativity (1901), Percy Bysshe Shelley's A Defence of Poetry (1904), the Biblical Book of Ruth (1904), and William Blake's Songs of Innocence and Experience (1906).

Among the works he published were Frank Lloyd Wright's The Japanese Print (1912) and Experimenting with Human Lives (1923), and Alice Corbin's Red Earth: Poems of New Mexico (1920).

He published Henry Blake Fuller's Bertram Cope's Year (1919), a novel about homosexuals in Chicago and an early example of gay literature in America.

He also published his own account of his life and art, in which he stated that the Chicago artists of his generation saw themselves as "peculiarly American" practitioners who disregarded "European, eastern or conventional rules for guidance in saying what they wanted to say.