Jerry Seinfeld Jerry Seinfeld Actor Julia Louis-Dreyfus Elaine Benes Actor Jason Alexander George Costanza Actor Michael Richards Cosmo Kramer Actor Barney Martin Morty Guest Star Liz Sheridan Helen Guest Star Bruce Davison Wyck Guest Star John O'Hurley J. Peterman Guest Star Christine Taylor Ellen Guest Star Jed Rhein Steven Koren Guest Star Tony Colitti Leader Guest Star David Moscow Lomez Jr. Guest Star Yunoka Doyle Lydia Guest Star Dublin James Maurice Guest Star Justine Slater Melissa Guest Star Larry David Executive Producer George Shapiro Executive Producer Howard West Executive Producer