In 1998, Sudduth returned to the stage, playing Fabian in the Broadway revival of "Twelfth Night". That same year he gave a good performance in the disappointing "54", playing the demanding father of Ryan Phillippe's starstruck club employee Shane O'Shea. He was better suited for a turn opposite Robert De Niro in John Frankenheimer's action thriller "Ronin" (also 1998). Here he played Larry, the adept getaway driver member of a group of espionage experts. He returned to the stage in the 1999 revival of Eugene O'Neill's "The Iceman Cometh", playing Chuck Morello, a bartender planning to marry a prostitute. That same year was featured in "Flawless" with Robert De Niro, playing the security guard pal of the veteran actor's unhappy invalid Walt.
1999 marked the beginning of Sudduth's first television regular role. He starred on the popular NBC series "Third Watch" as John 'Sully' Sullivan, a police officer working the 3 pm to midnight shift. Work-obsessed to a fault and not above stretching the truth, Sully wasn't a perfect police officer, but Sudduth's nuanced portrayal made for a truly human character and some uniquely good television. The actor put his average guy-next-door appeal to good use in "Third Watch", convincingly looking the part of a veteran beat cop and giving the eye candy-heavy series a dose of reality.
A musician as well as an actor, Sudduth is a founding member, lead guitarist and vocalist of the NYC-based rock band Minus Ted, which more recently drafted Kohl Sudduth, his younger brother and a fellow actor, on bass.