The son of actor Richard Cusack and younger brother of comic actress Joan Cusack, John Cusack started his career at the age of eight, under the guidance of his theatrically active mother. He made his stage bow with Evanston's Pivan Theatre Workshop and quickly went on to do commercial work, becoming one of Chicago's busiest commercial voice-over artists.
Although Cusack began to emerge as an actor during the heyday of the Brat Pack, and appeared in a number of "teen" movies, he managed to avoid falling into the narrowly defined rut the phenomenon left in its wake. After making his film debut in 1983's Class, he had a brief but painfully memorable appearance as a member of Anthony Michael Hall's nerd posse in Sixteen Candles (1984). Bigger and better opportunities came Cusack's way the following year, when he achieved a measure of stardom with his portrayal of a sexually anxious college freshman in The Sure Thing (1985). The same year, he gained further recognition with his starring roles in Better Off Dead (which also granted him a degree of cult status) and The Journey of Natty Gann.