He was the most famous “saloon comic” in Boston during the 1980s, the heyday of the Boston comedy scene. The DVD release When Standup Stood Out (2006) details Clarke’s early career and affiliations with other famous Boston comics, such as Steven Wright and Denis Leary, his good friends. In 1980, Clarke wrote and starred in a local television show Lenny Clarke’s Late Show featuring Wright and Leary, in collaboration with Boston comedy writer Martin Olson. Clarke and Olson were roommates, and their apartment, known by comedians as “The Barracks”, was a notorious “crash pad” for comics visiting Boston, per the film.

He had appeared on ESPN’s 30 for 30 – 4 Days in October alongside ESPN sports and pop culture columnist Bill Simmons as a narrator giving insight on the 2004 ALCS comeback by the Red Sox against the New York Yankees.

In 2006, Clarke and Leary appeared on television during a Red Sox telecast and, upon realizing that Red Sox 1st baseman Kevin Youkilis is Jewish, delivered a criticism of Mel Gibson’s anti-semitic comments.

In 2007, Clarke played the role of Ron Abbot on the short lived Fox comedy series The Winner. The show was cancelled after six episodes due to low ratings on May 16, 2007.

Clarke is also an occasional guest on the WEEI radio shows in Boston. It was on this show that he announced he would be a regular on the 2009 Fox Sitcom Brothers as the racist neighbor who is married to a black woman. He wound up appearing in three episodes before the series was cancelled. In the 2011-12 TV season, he landed a role as the main character’s father on the NBC mid-season replacement sitcom Are You There, Chelsea?.