Ron Howard Richie Cunningham Actor Henry Winkler Arthur "Fonzie" Fonzarelli Actor Tom Bosley Howard Cunningham Actor Marion Ross Marion Cunningham Actor Anson Williams Warren "Potsie" Weber Actor Don Most Ralph Malph Actor Erin Moran Joanie Cunningham Actor Al Molinaro Al Delvecchio Guest Star James Randi The Amazing Randi Guest Star George Fenneman George Fenneman Guest Star Kathi Marshall Louise Guest Star Scott Marshall Louie Guest Star Jerry Paris Director