Sid Newman is Old Man in The Nap (Season 8 Episode 18).
Siobhan Fallon Hogan is Tina Robbins in 3 episodes. The first: The Deal (Season 2 Episode 9).
Sonya Eddy is Rebecca de Mornay in The Muffin Tops (Season 8 Episode 21) and in The Bookstore (Season 9 Episode 17).
Spice Williams Crosby is Woman Carrying George in The Butter Shave (Season 9 Episode 1).
Stanley Anderson is Judge Arthur Vandelay in The Finale (Season 9 - Episode 22).
Stephen Lee is Conrad, Connie, or Con, whatever you prefer. He portrays the indecisive contractor of Jerry's new kitchen cabinets. He appears in The Nap (Season 8 Episode 18).
Stephen McHattie is Dr. Reston in 4 episodes. The first: The Pitch (Season 4 Episode 3).
Stephen Pearlman is Mr. Goldstein in The Raincoats (Season 5 Episode 18).
Stephen Root is Mr. Lager, the manager of Federal Home Savings Bank, in The Invitations (Season 7 Episode 24).
Stephen Tobolowsky is Tor Eckman, the holistic healer in The Heart Attack (Season 2 Episode 8).
Steve Hytner is Kenny Bania in 6 episodes. The first: The Soup (Season 6 Episode 7).