FC Twente Born in
Borne, Wieffer played youth football for RKSV NEO aged 5 before joining
FC Twente's academy at the age of 10. He made one
Derde Divisie appearance for
Jong FC Twente in the 2017–18 season, He made his league debut in a 2–0 win over
TOP Oss in March 2019. FC Twente were promoted to the
Eredivisie as champions of the
Eerste Divisie in the same season, but Wieffer did not appear for FC Twente's first team in the
2019–20 season.
Excelsior In June 2020, Wieffer joined
Excelsior on a free transfer, signing a three-year contract with the club. He made his debut for Excelsior on 29 August 2020, replacing
Mitchell van Rooijen in a 1–6 win against
Jong PSV in the
Eerste Divisie. He was sent off with a red card in the league game against
FC Eindhoven on 9 October 2020 (1–1). On 5 February 2021, Wieffer scored his first goal in professional football in a 0–2 win against
FC Volendam. He was named Excelsior Player of the Year after his first season at the club, winning 26% of the votes. On 29 May 2022, he scored in the
penalty shoot-out as Excelsior beat
ADO Den Haag in the final of the
play-offs to promote to the Eredivisie
Feyenoord In June 2022, Wieffer moved to
Feyenoord on a four-year contract. After getting injured in a friendly against
Red Bull Salzburg in pre-season, he made his debut for Feyenoord and in European football on 8 September 2022, coming on as a substitute for
Javairô Dilrosun in a 4–2 defeat against
Lazio in the
UEFA Europa League. Three days later, he replaced Dilrosun during a 3–0 victory against
Sparta Rotterdam to make his Eredivisie debut. On 13 January 2023, Wieffer scored his first goal for the club while also providing an assist in a 3–1 cup win over
PEC Zwolle, what was his first start for the club. He was named Feyenoord Player of the Month for January 2023 and February 2023. On 13 April 2023, Wieffer scored his first goal in a European club competition, scoring the only goal in a 1–0 win over
AS Roma in the
quarter-finals of the UEFA Europa League. He assisted goals of
Oussama Idrissi and
Igor Paixão on 14 May 2023 as Feyenoord beat
Go Ahead Eagles 3–0 to secure its sixteenth Eredivisie title. On 4 August 2023, Wieffer played the full game as Feyenoord lost the
Johan Cruyff Shield 0–1 to
PSV Eindhoven. Wieffer made his
UEFA Champions League debut on 19 September 2023, in a 2–0 win against
Celtic. He scored his first goal in the competition on 28 November 2023, during a 1–3 defeat against
Atlético Madrid. Ahead of the
KNVB Cup final on 21 April 2024, Wieffer suffered a thigh injury, ruling him out for the remainder of the season. Feyenoord went on beat
NEC 1–0 in the cup final and finish in second place in the
Eredivisie. During his time at Feyenoord, Wieffer played 54 league games, in which Feyenoord averaged 2.52 points, recording a joint-record for players in the Eredivisie with over 50 games played.
Brighton and Hove Albion On 5 July 2024, Wieffer joined
Premier League club
Brighton & Hove Albion, signing a contract until June 2029. With a reported fee of €30 million, it became Feyenoord's most expensive outgoing transfer of all-time. He made his Premier League debut in Brighton's opening match against
Everton on 17 August 2024, where he'd register an assist as the Seagulls would go on to win 3–0. On 11 April 2026 he scored two goals in a game for the first time in his career as Brighton won 2-0 at
Burnley. ==International career==