Sporting CP Fernandes is a youth product of his local club
Olhanense, and moved to
Sporting CP's youth academy in 2016. He was promoted to their
B-team for the 2021–22 season. On 14 October 2022, Fernandes signed a professional contract with the club tying him until 2027 with a release clause of €60 million. He made his professional and senior debut with Sporting as a late
substitute in a 3–1
Primeira Liga win over
Casa Pia on 22 October 2022. On 29 August 2023, Primeira Liga club
Estoril announced the signing of Fernandes on a season-long
loan from Sporting.
Southampton On 20 August 2024, Fernandes joined
Southampton on a five-year contract. He made his debut for the club on 24 August 2024 in a 1–0 home defeat against
Nottingham Forest after he replaced
Taylor Harwood-Bellis in the 76th minute. On 28 August 2024, Fernandes scored his first goal for the club in a 5–3 away victory against
Cardiff City in the
EFL Cup.
West Ham United On 29 August 2025, Fernandes joined
West Ham United on a five-year contract, for a fee reported to be “more than £40m”. He became the club's third-biggest signing, behind the £45m paid for
Sebastien Haller and the £51m paid for
Lucas Paquetá. On 14 December, he scored against Aston Villa after 29 seconds, making it the fastest Premier League goal of the season. The game ended 3–2 to Villa. ==International career==