That '70s Show is a sitcom.
Debra Jo Rupp ( born February 24 , 1951 ) is an American film and television actress , best known for her roles as Kitty Forman on the Fox sitcom That '70s Show and Alice Knight-Buffay on the third , fourth and fifth seasons of Friends . That '70s Show . The main adult cast members were Debra Jo Rupp , Kurtwood Smith , Don Stark , Tommy Chong and Tanya Roberts .