Leonard King "Len" Lesser (December 3, 1922 – February 16, 2011) was an American actor. He was known for a key role in the Clint Eastwood movie Kelly's Heroes and his recurring role as Uncle Leo in Seinfeld, which began during the show's second season in "The Pony Remark" episode.On February 16, 2011, Lesser died of cancer-related pneumonia^[6] in Burbank, California, at the age of 88 

Jerry Seinfeld, after Lesser's death, said of him, "Len was one of our favorites. We always loved having him on the show. I'll never forget when Uncle Leo was in prison and tattooed 'Jerry Hello' on his knuckles. He was a very sweet guy." Other Seinfeld castmate Jason Alexander tweeted,