Nuno Miguel Valente Santos, an attacking midfielder born in Porto, is not to be confused with the Sporting CP winger of the same name. He came through the academies of both of his home city's major clubs, Boavista and FC Porto, before joining Benfica's youth system in 2012.

He made his debut for Benfica B in August 2017 and scored his first senior goal in January 2018. Over two and a half seasons in the reserve side he registered 60 league appearances with 13 goals, eventually wearing the captain's armband, and also featured prominently in the UEFA Youth League. Loans followed to Moreirense in the second half of 2019/20, where he made his Primeira Liga debut, then to Boavista and to Paços de Ferreira, for whom he scored five goals in 31 matches in 2021/22.

With no route into Roger Schmidt's first team, Santos left permanently on 5 August 2022, signing a two-year deal with Major League Soccer's Charlotte FC. He scored once in MLS before returning to Portugal in 2023.