[9] Fernandes played most of his youth football with Boavista, starting his career as a centre-back, before being converted to an attacking midfielder at the age of 15, following a loan to Pasteleira.

After his girlfriend moved to Italy, Fernandes quickly learned the language and began settling in the country, being nicknamed the "Maradona of Novara" and the "Mini Rui Costa".

[22] On 27 June 2017, after returning from the UEFA European Under-21 Championship, Fernandes joined Sporting CP on a five years deal, for a reported fee of €8.5 million plus bonuses.

[25][26] Fernandes' first appearance in the UEFA Champions League group stage was on 12 September, where he put the visitors 3–0 ahead in the 43rd minute of an eventual 3–2 win at Olympiacos.

[29][30] Despite the events, the team agreed to play in the final of the Taça de Portugal scheduled for the following weekend,[31] eventually losing to Desportivo das Aves.

[33] Four days later he signed a new five-year contract with a €100 million release clause,[34] having turned back on his original decision to leave the Estádio José Alvalade following the departure of club president Bruno de Carvalho, and being given an improved salary in the process.

[36] On 5 May, he scored a hat-trick in an 8–1 away rout of Belenenses SAD, in the process becoming the highest-scoring Portuguese midfielder in a single season of all time, with 31 goals to his name.

[42] On 28 November, he scored twice and assisted the other two goals in a 4–0 victory over PSV Eindhoven, which guaranteed Sporting qualification to the knockout stages of the UEFA Europa League.

[73] On 26 May, Manchester United drew 1–1 against Villarreal after extra-time, in the Europa League Final, but eventually lost on penalties, despite Fernandes netting his spot kick in the shoot-out.

[75] He then scored in the team's next home game against Newcastle United,[76] before missing a last minute penalty against Aston Villa two weeks later that would have salvaged a 1–1 draw.

[79] On 2 December, Fernandes made his 100th appearance for the club, opening the scoring in United's 3–2 home win over rivals Arsenal at Old Trafford.

[86] On 3 January 2023, Fernandes made his 150th appearance for the club, assisting Marcus Rashford's goal in United's 3–0 home win over Bournemouth.

[91] In the 2023 FA Cup final, Fernandes equalised for United through a penalty in an eventual 2–1 defeat to local rivals Manchester City.

[94] On 26 August, Fernandes scored his first goal of the season, netting a penalty, and also assisting Casemiro in a 3–2 comeback win over Nottingham Forest.

[97][98][99] In January 2024, during the winter transfer window, Fernandes was the recipient of a contract offer worth €100 million from Saudi Pro League side Al-Hilal.

[106] After the match, pundit and former United midfielder Roy Keane praised Fernandes: "I've been critical of Bruno over the years, but I've been proven wrong, his leadership was outstanding.

[113] He made his 250th appearance for the club on 11 November, scoring the opening goal and assisting Alejandro Garnacho in a 3–0 win against Leicester City.

[118] In June, Fernandes took part in the 2017 UEFA European Under-21 Championship, helping Portugal to a group stage finish, and scoring a goal against Serbia in the opening match.

[127][128] Fernandes' first World Cup game took place on 15 June, when he played 66 minutes in a 3–3 group stage draw against Spain, being booked in the process.

In the UEFA Nations League Finals, Fernandes played both matches as Portugal defeated the Netherlands 1–0 in Porto to win the trophy.

[134] Fernandes was named in Portugal's final squad for the delayed UEFA Euro 2020 tournament, appearing in all games of the eventual round of 16 exit.

After being heavily fatigued and overshadowed by other teammates, he was dropped from the starting lineup for the final group stage match as Portugal failed to qualify for the round of 16.

[145] His World Cup form continued during the UEFA Euro 2024 qualifiers in March, providing two assists and a brace against Bosnia and Herzegovina in a 3–0 win on 17 June.

[147] On 11 September, he scored a goal and provided a hat-trick of assists in a 9–0 home defeat of Luxembourg, the former's biggest win in international history.

[148] In the reverse fixture against Slovakia, on 13 November, Fernandes provided a brace of assists in a 3–2 win, leading Portugal to qualify for Euro 2024, marking the nation's fastest qualification to a major tournament in their history.

[152] In Portugal's round of 16 match against Slovenia, he played the full 120 minutes and scored the team's second kick of the penalty shootout which they won 3–0.

[154] An attacking midfielder, Fernandes is a direct, energetic box-to-box playmaker who is capable of both taking on defenders and setting the rhythm of play.

[155] During his time at Manchester United, under Erik ten Hag, Fernandes also played on the right wing on many occasions, due to his crossing ability, which made him an effective assist provider.

"[160] In 2023, Manchester City and Belgian midfielder Kevin De Bruyne rated him as the best player in his position in Premier League commenting, "I think he's [Fernandes] a creative machine and just in general.

[163] Former Manchester United coach Ole Gunnar Solskjær stated that Fernandes was a "bit of a mix between Paul Scholes and Juan Sebastián Verón".