Oscar Schwartau

Brøndby

On 17 May 2022, Schwartau signed a three-year contract with Brøndby IF which tied him to the club until the summer 2025. He was officially promoted to the first team during 2022–23 pre-season and assigned the number 41 jersey. He made his professional debut on 17 July 2022 in the season opener of the Danish Superliga against AGF at the age of 16 years and 61 days. In doing so, he became the youngest player in club history and also became the first player born in 2006 to make an appearance in the Danish Superliga. On 14 August, he scored his first goal in a 2–0 win against OB becoming the club's youngest league goalscorer, and second-youngest overall in Danish Superliga.

Norwich City

On 24 August 2024, English Championship club Norwich City signed Schwartau on a four-year deal with a club option of an extra year. The fee was undisclosed, but reported to be £2 million with Brøndby retaining a 15% sell-on clause. He scored his first goal for the club on 26 December 2024 against Millwall at Carrow Road. At the end of Norwich City's 2025–26 season, Schwartau was named as the young player of the season.

Schwartau has represented Denmark at various youth international levels. He made his debut for the Denmark under-16 national team on 17 September 2021 in a friendly match against Portugal, which ended in a 1–1 draw in Kolding. Over the course of his U16 tenure, he earned seven caps and scored three goals before aging out of the squad. Following his time with the U16s, Schwartau progressed to the Denmark U17 team, making his first appearance on 21 September 2022 in a 4–2 friendly victory over Austria in Vienna. His rapid development earned him a call-up to the Denmark under-19s just two months later, despite being younger than many of his peers. In November 2022, head coach Jens Fønsskov Olsen included him in the squad for two friendly matches against the Czech Republic, held in San Pedro del Pinatar, Spain. Schwartau featured in both fixtures, contributing to Denmark's 3–2 and 3–1 wins, respectively.

As of match played 2 May 2026