His first Broadway play was a stage adaptation of the classic tale of Peter Pan in 1915.
Some of McClelland's other plays he performed in include Sylvia, Back Here, Scarlet Pages, Lady Beyond the Moon, The Mask and the Face, Ah, Wilderness!, To My Husband, The Night Before Christmas, Yankee Point, Make Yourself at Home, State of the Union, Miss Liberty, Our West of Eighth, and Mid-Summer.
[2] Two years later, McClelland, who was 14 at the time, appeared in his first film continuing his career as a child actor.
McClelland made his first television appearance in 1950 on the anthology series Armstrong Circle Theatre.
McClelland co-starred with Darren McGavin and Jan Miner on the television series Casey, Crime Photographer.