British poet noted for his light verse, which frequently deals with sexual themes. He wrote children's poems and poetry on serious subjects as well.

Soon after Ewart's 17th birthday his poem “Phallus in Wonderland” was published, beginning a long career of writing poetry that ranged from whimsical to bawdy. Ewart was educated at Christ's College, Cambridge (B.A., 1937; M.A., 1942), and published his first collection, Poems and Songs, in 1939. For the next 25 years he almost completely abandoned poetry; he served in the Royal Artillery during World War II and worked as an advertising copywriter (1952–71). His second collection, Londoners (1964), was in general more serious in tone and showed affinities with the poetry of John Betjeman (Betjeman, Sir John).

With Pleasures of the Flesh (1966) and The Deceptive Grin of the Gravel Porters (1968), Ewart's characteristic approach was set; he intermingled poems of serious autobiography, social satire, and sexual humour. A strain of melancholy pervades his later poetry, in which he examines such topics as cruelty and death. Several of his collections, including The Learned Hippopotamus (1986) and Caterpillar Stew (1990), were written for children, and his verse is gathered in The Collected Ewart 1933–1980 (1980) and Collected Poems 1980–1990 (1991). Ewart also edited several poetry anthologies.