Dawber's professional breakthrough came when Marshall chose her, despite her having relatively little acting experience and not having auditioned for the part, as one of the two title characters of the ABC sitcom Mork & Mindy, which ran from 1978 to 1982. She portrayed Mindy McConnell, the comedic foil and eventual love interest for the extraterrestrial Mork from the planet Ork, played by a then-unknown Robin Williams.