Jerry Seinfeld Jerry Seinfeld Actor Julia Louis-Dreyfus Elaine Benes Actor Jason Alexander George Costanza Actor Michael Richards Cosmo Kramer Actor Lloyd Bridges Izzy Mandelbaum Guest Star Liz Sheridan Helen Guest Star Barney Martin Morty Guest Star John O'Hurley J. Peterman Guest Star Chelsea Noble Danielle Guest Star O'Neal Compton Earl Haffler Guest Star Lisa Mende Carol Guest Star Gene Dynarski Izzy Mandelbaum Jr. Guest Star Marco Rodríguez Guillermo Guest Star Joe Urla Dugan Guest Star Jill Talley Gail Guest Star Todd Jeffries Blaine Guest Star Larry David Executive Producer George Shapiro Executive Producer Howard West Executive Producer Andy Ackerman Director Steve Koren Writer