In 1980, at the age of 18, he had his first movie role as an extra in the movie Ordinary People. Shortly after his college graduation, he obtained his first major role as Mike Horton on Days of Our Lives. Weiss also starred in the NBC-TV prime time drama The Pretender for four seasons as the lead character Jarod. Weiss also had roles in the movie Jeffrey, the animated series The Legend of Tarzan, and a recurring role on Crossing Jordan. He voiced "The Nameless One", the protagonist of computer game Planescape: Torment.