Early career Simons joined the
youth setup of
Barcelona in 2010 from Club Deportivo Thader of
Alicante, and quickly progressed to become one of the
Catalan club's most highly-rated youth players, with English club
Chelsea reportedly attempting to sign him at a young age. Described as a "prodigy", he joined the group of players represented by agent
Mino Raiola in 2017.
Paris Saint-Germain player in 2020|277x277px In July 2019, Simons moved to French club
Paris Saint-Germain (PSG), having failed to agree a new contract with Barcelona. His three-year contract with the Parisian club was reportedly worth up to €1 million annually. On 10 February 2021, Simons made his professional debut for PSG, coming on as a substitute for
Julian Draxler in a 1–0
Coupe de France win over
Caen. He made his
Ligue 1 debut as a substitute in a 4–1 win over
Strasbourg two months later. On 19 May 2021, he won his first professional trophy, the Coupe de France. in 2020 Ahead of the
2021–22 season, Simons was included in the first-team preparation and pre-season by manager
Mauricio Pochettino. On 18 August, Simons was sent back to train with the under-19 squad coached by
Zoumana Camara. He eventually made his first appearance of the season for PSG in a 3–0 cup win over
Feignies Aulnoye on 19 December, his first ever professional start. On 3 January 2022, Simons recorded his first senior assist in a 4–0 cup win over
Vannes, a pass for
Kylian Mbappé. His first league appearance of the 2021–22 season came in a 1–1 draw against
Lyon on 9 January, where he came on as a 69th-minute substitute. On 31 January, Simons missed the final penalty in a 6–5
penalty shoot-out defeat to
Nice in the round of 16 of the Coupe de France. On 11 February, he made his first Ligue 1 start in a 1–0 win over
Rennes at the
Parc des Princes. At the end of the season, Simons won the Ligue 1 title, his first professional league title.
PSV On 28 June 2022, Simons signed for
Eredivisie club
PSV Eindhoven on a five-year contract. Although he was initially expected to extend his contract with PSG and join PSV on
loan, the situation changed when PSV no longer wanted a loan deal. However, PSG negotiated a reported €6 million buy-back clause in Simons's contract, effective in 2023. Simons scored his first career goal on his PSV debut, a 5–3 win over rivals
Ajax in the
Johan Cruyff Shield on 30 July 2022. On 7 August, in his first Eredivisie game, he provided an assist for
Johan Bakayoko, who opened the scoring in a 4–1 victory against newly-promoted
Emmen. Simons made his European debut with PSV in the
UEFA Champions League qualifiers, and scored his first European goal in a 5–1
UEFA Europa League group stage victory away to
Zürich on 6 October. In the
2023 KNVB Cup final, he provided the assist for
Thorgan Hazard's goal as PSV came out victorious over Ajax on penalties. In the final match of the
2022–23 Eredivisie season on 28 May 2023, Simons scored a
brace, including a stoppage-time winner, in a 2–1 victory over
AZ, securing second place for PSV and a spot in the Champions League qualifiers for the following season. With nineteen goals, he shared the Eredivisie top scorer award with
Anastasios Douvikas of
Utrecht. On 16 July 2023, it was announced by PSV that Simons had departed the club's training camp in order to finalize a transfer back to Paris Saint-Germain.
Return to Paris Saint-Germain On 19 July 2023, Simons returned to Paris Saint-Germain, signing a four-year contract after the club triggered a reported €6 million buy-back clause in his PSV contract, where Simons had the final say on his return. He was assigned the number 20 jersey. On 12 August 2023, he made his debut for the club in a 3–0 win over
Bayern Munich in the
2023 DFL-Supercup. On 25 August, he scored his first Bundesliga goal in a 5–1 win over
VfB Stuttgart, a match in which he also recorded two assists. On 25 October, Simons scored his first goal in the Champions League in a 3–1 victory over
Red Star Belgrade. In addition, he was named player of the match, as he also provided an assist; aged 20 years and 187 days, he became the youngest Dutch player to both score and assist in the competition since
Arjen Robben in 2003. In the second fixture against Red Star Belgrade on 7 November, Simons scored the opening goal in a 2–1 win, securing qualification to the round of 16. By the end of the season, Simons had scored eight goals and registered eleven assists in thirty-two Bundesliga appearances, finishing joint-second in assists and helping RB Leipzig to a fourth-place finish. On 5 August 2024, Simons was again loaned out to RB Leipzig for the rest of the season. On 12 January 2025, on the occasion of his first start since October 2024 due to an injury, Simons scored a brace in a 4–2 victory over
Werder Bremen, his first brace in the Bundesliga on his 40th appearance in the competition.
RB Leipzig On 30 January 2025, RB Leipzig signed Simons on a permanent deal from Paris Saint-Germain for €50 million plus €31 million in potential bonuses.
Tottenham Hotspur On 29 August 2025,
Premier League club
Tottenham Hotspur announced the signing of Simons on a five year minimum contract, for a fee believed to be around £51.8 million. The transfer was noteworthy due to Simons's decision to sign for Tottenham in spite of the well-documented interest of their London
rivals Chelsea, who had courted him throughout the summer 2025 transfer window. Simons made his debut for Tottenham on 13 September 2025, starting and assisting the first goal in a 3–0 away victory against
West Ham United. On 6 December, he scored his first goal for the club and registered an assist in a 2–0 home win over
Brentford. On 9 December, he scored his first Champions League goal for Spurs in a 3–0 win over
Slavia Prague. On 25 April 2026, Simons suffered an injury during a 1–0 away victory against
Wolverhampton Wanderers. The injury, a
ruptured anterior cruciate ligament of his right knee, meant he was ruled out for at least seven months, so would miss the rest of the season and the
2026 FIFA World Cup. ==International career==