Before the popularity of "Cruel Intentions", Thomas was featured on the TV series "New York Undercover" (Fox) in 1996 and "Nick Freno: Licensed Teacher" (The WB) in 1997. He made his film debut with a role in the military drama "Courage Under Fire" in 1996, and followed up the following year with turns in "Picture Perfect" and "Conspiracy Theory". In 1998, he was featured in the high school graduation party-set comedy "Can't Hardly Wait", with a much larger role than his 'Jock No. 2' credit indicated. He played one of three sidekicks to Peter Facinelli's dumped golden boy Mike, a football player unwilling to give up his long-term girlfriend as per Mike's plan. Following his TV series debut on the drama "The District" (CBS, 2000- ), he co-starred opposite Julia Stiles in "Save the Last Dance", a popular 2001 dance-themed interracial romance. He followed that success up with an uncredited turn in the teen comedy spoof "Not Another Teen Movie!" (2001) as Black Guy at Party, and a stint in the teen-skewing horror market in "Halloween: Resurrection" (2002), before getting a fresh round of exposure playing Jimmy James, a college student who tries to impress everyone with his knowledge, in the hit comedy "Barbershop" (2002) and its sequel "Barbershop 2: Back in Business" (2004).
In addition to screen credits, the stage trained Thomas has had a relatively prolific career in theater, working extensively in regional productions including a starring turn in a 1997 musical adaptation of "Cooley High" and a featured role in the New York Shakespeare Festival's "Timon of Athens" in 1996.