The actor passed away at his home in California not long after he was diagnosed with cancer, reports Deadline.
Einstein, best known for playing Marty Funkhouser on the Larry David sitcom, appeared in Curb Your Enthusiasm from 2004 to its most recent season.
The Emmy-award winning star was also a writer for The Smothers Brothers Comedy Hour, The Sonny and Cher Comedy Hour and Van Dyke and Company.
His brother, Albert Brooks, paid tribute to the actor, tweeting: "R.I.P. My dear brother Bob Einstein. A great brother, father and husband. A brilliantly funny man. You will be missed forever."