Katie Layman is Cynthia, the Mentor in The Fatigues (Season 8 Episode 6).

Katy Selverstone is Siena in The Face Painter (Season 6 - Episode 22).

Kay E. Kuter is the head Latvian Orthodox priest in The Conversion (Season 5 Episode 11).

Keith Hernandez is Himself in The Boyfriend (Season 3 Episode 17).

Keith Morrison is the Newscaster in The Trip (Season 4 - Episodes 1 and 2).

Keith Sellon-Wright is Guy in The Muffin Tops (Season 8 Episode 21).

Kellie Waymire is Vivian in The Blood (Season 9 Episode 4).

Kelly Coffield Park is Noreen in The Pledge Drive (Season 6 Episode 3) and in The Chinese Woman (Season 6 Episode 4).

Kelly Perine is Usher in The Postponement (Season 7 Episode 2).

Ken Hudson Campbell is Ken in The Seven (Season 4 Episode 14).

Ken Kerman is a police officer in The Beard (Season 6 - Episode 16).

Ken Takemoto is the Chairman in The Opposite (Season 5 Episode 22).

Ken Thorley is Vic the car salesman in The Mom and Pop Store (Season 6 - Episode 8).

Kenneth Ryan is Mr. Burns in The Maestro (Season 7 Episode 3).

Kevin Dunn is Joel Horneck, a childhood friend of Jerry's in Male Unbonding (Season 1 Episode 4).

Kevin McDonald is Steve (Denim Vest) in The Strike (Season 9 Episode 10).

Kevin Page is Stu Chermack in five episodes. The first The Pitch (Season 4 Episode 3).

Kevin Steinberg is Waiter in The Andrea Doria (Season 8 Episode 10).

Kieran Mulroney is Timmy in The Implant (Season 4 Episode 19).

Kim Chase is Charmaine in The Wig Master (Season 7 Episode 18).

Kim Gillingham is Assistant in The Puffy Shirt (Season 5 Episode 2).

Kim Myers is Pam in The Soul Mate (Season 8 Episode 2).

Kim Zimmer is Lenore Walker in The Diplomat's Club (Season 6 - Episode 21).

Kimberley Kates is Diane in The Robbery (Season 1 Episode 3).

Kimberley LaMarque is Teller in Male Unbonding (Season 1 Episode 4).

Kimberley Norris or Kimberley Guerrero is Winona, Elaine's poker friend in The Cigar Store Indian (Season 5 Episode 10).

Kimbely Campbell is Tawni in The Conversion (Season 5 - Episode 11).