Acting came to Stephen Quadros almost by default. He originally moved to Los Angeles to pursue a career as a drummer, where he achieved local success and radio airplay with the band SNOW, which featured Carlos Cavazo (Quiet Riot, Ratt) on guitar.

Stephen was even flown to New York to audition for the group KISS. But when repetitive hand injuries aborted his percussive pursuits, Quadros dove into acting, studying with a variety of respected teachers, including: Cameron Watson, William Alderson, Stella Adler, Milton Justice, Arthur Mendoza, Scott Bernstein, Michelle Danner and Mark Haining. As an actor Quadros has starred, guest-starred or co-starred in over 50 films and television shows, working with such Hollywood luminaries as Bryan Cranston, Kathryn Bigelow, Miles Teller, Nicolas Winding Refn, John Hawkes, Cuba Gooding Jr.