Lewis was born in Newport Beach, California, the son of Nancy, a nurse, and Gregory Lewis, a court judge; the two are divorced. He has three siblings, Sean, Katie and Nicole. In his teens he attended Los Alamitos High School in Los Alamitos, California. He attended college in San Diego, California, where he became a member of the Delta Upsilon Fraternity. Fellow fraternity brothers included Marc Iadanza (son of Tony Danza) and Jack Gilardi Jr. (son of Annette Funicello and Jack Gilardi). After college he started modeling, first in Paris and then with star status in Milan in the late 1990s for some of the biggest names in fashion, including Guess?, Tommy Hilfiger and Hugo Boss.