Mamadou Loum N'Diaye (born 30 December 1996) is a Senegalese professional footballer who plays as a defensive midfielder for F.C.

Loum made his professional debut in the Segunda Liga for S.C. Braga B on 15 August 2015 in a game against Gil Vicente F.C., as a 70th-minute substitute for Carlos Fortes.

[9] On 23 July 2021, after featuring rarely for Porto, Loum was loaned to La Liga side Deportivo Alavés for the 2021–22 campaign.

He made his debut for the senior team on 26 March 2019 in a friendly against Mali, playing the full 90 minutes of a 2–1 win in Dakar.

[14] He was called up for the 2021 Africa Cup of Nations, which the team won in Cameroon at the start of the following year; his one appearance was a goalless draw with neighbours Guinea in the second group game.