He was cast as the building superintendent on Louis C.K.'s HBO show Lucky Louie, and appeared with a recurring role in Louis C.K.'s FX series Louie, which began airing on June 29, 2010. In one episode, Louie aggressively argues with Di Paolo's character about the latter's dislike of Barack Obama, to the point that a physical fight breaks out and Di Paolo's character hurts his hand. Louie then takes his friend to the hospital where they have "a genuine heart-to-heart conversation about the difficulties of marriage." In the series, Louie (like his creator/portrayer) is divorced and shares joint custody of his children with his ex-wife. Di Paolo's character is "married happily, but he has no children, and his wife and he have passed that sort of point where they can't have kids and now they're faced with just each other 'til one of them is going to lose the other. And there's a melancholy feeling to that. But I envy it, because I'm alone," said C.K. in an interview.