Cosmo Kramer, usually referred to as simply "Kramer", is a fictional character on the American television sitcom Seinfeld (1989–1998), played by Michael Richards.The character is loosely based on comedian Kenny Kramer, Larry David's former neighbor across the hall. Kramer is the friend and neighbor of main character Jerry Seinfeld, residing in Apartment 5B, and is friends with George Costanza and Elaine Benes.