Riley played Charlie Hogan, one of his best-known roles, in the 1986 film Stand by Me, and also received notice for his portrayal of Dave Frazier in the 1987 comedy Summer School. He made notable appearances as a thief who steals money from Steve Martin's character's wallet in Planes, Trains, and Automobiles and as a naive metalhead customer whom Judge Reinhold can not bear to rip off after discovering his girlfriend is pregnant in Ruthless People. He also made guest appearances on such TV shows as Knots Landing, Growing Pains, Amazing Stories (in a special hour-long episode directed by Steven Spielberg), and Airwolf. Riley was raised in Irvine, CA. Gary's last role to date was as a thug in Fear, alongside Mark Wahlberg. Gary participated in the Summer School Q&A at New Beverly Cinema in the summer of 2013.