Marc John Jefferies is an American actor.

Jefferies debuted his career when he was a child in the 1995 drama Losing Isaiah. He was also featured as a child spokesman in commercials for PeoplePC.

He appeared in many popular films when he was younger, including The Haunted Mansion, Stuart Little 2, Charlie's Angels: Full Throttle, and Spider-Man 2. He was Young Dre in Brown Sugar. He also did voiceovers in the films Finding Nemo and Monsters Inc. He played Derrick on the NBC sitcom The Tracy Morgan Show.

In 2005, he portrayed the role of young Curtis '50 Cent' Jackson in Get Rich or Die Tryin'. In 2009's biopic of the late The Notorious B.I.G, "Notorious", he played the role of rapper Lil' Cease.  He guested during the third season of the TV series Dexter as Wendell, a drug dealer's doorman. He also appears in the feature Big Mommas: Like Father Like Son in 2012.

Marc John Jefferies was born on May 16, 1990 in New York City, New York. Aside from being an actor, Jefferies owned photography studio wherein his father who is a photographer by profession. His younger sister LaShawn Tináh Jefferies is an actress who has appeared in TV series which include Law & Order: Criminal Intent and the independent film Whitepaddy.