From 1944 through 1948 he teamed with comedy partner Hal March in the successful "Sweeney and March Show" for CBS Radio. He went on to appear as a supporting character in various sitcoms in the early days of television including the role of Gilmore Cobb in the television version of "My Favorite Husband" (1953–54) with co-stars Joan Caulfield and Barry Nelson. Sweeney made appearances on The Rifleman also in Our Miss Brooks during its last two seasons of production (1955–1956) working alongside Eve Arden, Gale Gordon and Richard Crenna.