Though Einstein was never a faculty member at Princeton, he was a fixture on campus. Einstein was a member of the Institute for Advanced Study and lived in Princeton from 1933 to his death in 1955. Though the Institute is independent from the University, Einstein did keep an office on campus; he also led a University seminar on the mathematics of relativity and often helped students with math problems.
See this photo and more snapshots from Princeton's progress through the decades by viewing Princeton: Then and Now.
Photo courtesy of the Princeton University Archives