His first gig was at the age of 14 months when he was in a Tide
commercial.
He began acting seriously at the age of 6.
During the making of American Outlaws (2001) Smith, the youngest of the cast, got the
nickname 'Secret Weapon' from the wranglers, for his rare talent to
handle guns.
His hobbies are acting, rock climbing, soccer, rollerblading, and
photography.
His father, Maurice Smith, is English-born (from London), and his mother, Terrea (Oster), is American-born (from California). Gregory has English, Ashkenazi Jewish, and small amounts of Dutch, German, Swedish, and Norwegian, ancestry.
Dual citizen of the U.S. and Canada.
Has two younger brothers, Andrew and Douglas, and a younger sister, Samantha.