Davis was born in Chicago, Illinois, the son of Romanian immigrants, Rose (née Marcus) and Fred Davis. He served in Europe during World War II and performed on the local stage and in radio productions after the war. Davis was also a pharmaceutical sales rep by trade but pursued acting after being fired from his sales job in the late '70s.
Davis started acting in the late 1970s. He appeared on Mister Rogers' Neighborhood in 1975 and in films such as Dunston Checks In, Holes, Code of Silence, Chain Reaction, Thief, Poltergeist III, and many others. He was nominated for a 1980 Joseph Jefferson Award for Actor in a Principal Role in a Play for his performance in Buried Child at the Northlight Theatre in Chicago, Illinois. He was again nominated for a Joseph Jefferson Award for Actor in a Principal Role in a Play for The Sunshine Boys at the National Jewish Theater in Chicago, Illinois in 1991. He was nominated for the last time for a 2001 Joseph Jefferson Award for Actor in a Principal Role in a Play for 2 1/2 Jews at the Apple Tree Theatre in Chicago, Illinois.