He began his career as a child actor on the variety stage and made his Broadway debut as a walk-on in the 1951 production of George Bernard Shaw's Saint Joan, starring Uta Hagen.

His most important contribution to the arts, however, remains his teaching career at the HB Studio[4] in Greenwich Village, founded by Herbert Berghof.

George Segal, Jeanie Columbo, Sandy Dennis, Barbra Streisand, Cyprienne Gabel, and Sandra McClain all studied under him.

He was a staple of Ben Bagley's New York musical revues; he can be heard on several of the recordings, notably Decline and Fall of the Entire World as Seen Through the Eyes of Cole Porter.

Hickey portrayed Don Corrado as sharp-witted and cunning, despite his frail physical state, and shared key scenes with Anjelica Huston and Jack Nicholson.