Marlo Stanfield is a fictional character on the HBO television drama The Wire, played by actor Jamie Hector. Stanfield is a young, ambitious, intelligent and ruthless gangster and head of the eponymous Stanfield Organization in the Baltimore drug trade. Marlo's organization starts out small-time, competing with the larger Barksdale Organization, but rises to the top of the Baltimore drug trade fairly quickly.

Marlo Stanfield began his reign by occupying corners along Eastern Avenue in West Baltimore. Marlo soon initiated war with the Barksdale Organization over territory.

The Barksdale Organization approached Marlo through lieutenant Preston Broadus to discuss exchanging the sharing of territory for a share of their high quality supply of drugs. Bodie had set up his own crew within Stanfield's established territory. Marlo refused to acknowledge Bodie and insisted that he move his crew away. Later Marlo had his dealer Fruit and his crew beat Bodie's team with baseball bats to prove that he wasn't going to lay down and let the Barksdale organization move into his territory. Stringer Bell visited Marlo personally to try to convince him to join the co-op; a group of Baltimore drug players who buy packages of narcotics together to receive discount and try to reduce the violence of their trade to avoid police attention. Marlo listened to Stringer without comment, and shortly after Stringer left, he warned Partlow to prepare for war.