Marcus R. Dixon is a fictional character on the television series, Alias. He has been one of Sydney Bristow's coworkers and the CIA's Director of Joint Task Force. He is portrayed by Carl Lumbly.

Carl Winston Lumbly is an American actor. He is known for his role as television's first brown superhero in M.A.N.T.I.S., Dick Hallorann in Doctor Sleep, NYPD detective Marcus Petrie on the CBS police drama Cagney & Lacey, CIA agent Marcus Dixon on the ABC espionage drama series Alias, and as the voice of J'onn J'onnz / Martian Manhunter in the animated series Justice League, Static Shock and Justice League Unlimited, all part of the DC Animated Universe. As a reference to his voice work as J'onn, Lumbly portrayed J'onn J'onnz's father, M'yrnn, on The CW's Arrowverse on Supergirl from 2017 until 2019. He also plays Isaiah Bradley, the first Black super-soldier in the Marvel Cinematic Universe (MCU) installments The Falcon and the Winter Soldier (2021) and the forthcoming Captain America: Brave New World (2025).