Vito D'Ambrosio is the cop in The Gum (Season 7 - Episode 10).
Walter Olkewicz is Nick, the Plaza Cable man in The Cadillac (Season 7 Episodes 14-15).
Warren Frost is Henry Ross in 5 episodes. The first: The Pitch (Season 5 Episode 10).
Wayne Knight plays Newman, Jerry's neighbor (5E apartment), lazy mailman and sworn enemy.
Wayne Wilderson is Walter in four episodes. The first The Summer of George (Season 8 Episodes 22).
Wesley Thompson is Poker Player in The Opposite (Season 5 - Episode 22).
Wilford Brimley is Henry Atkins, U.S. Postmaster General, in The Junk Mail (Season 9 Episode 5).
William Jackson is Doctor in The Diplomat's Club (Season 6 - Episode 21).
Winston J. Rocha is Security Agent in The Trip (Season 4 Episodes 1-2).
Yul Vazquez is Bob in 3 episodes. First: The Soup Nazi (Season 7 Episode 6).