Oscar Schwartau signed for Norwich City on 24th August 2024 on a four year contract with the club holding an option for an additional season. The fee was undisclosed but reported to be £2million.

Born in Sengelose in Denmark, Oscar played for youth teams Sengeløse GI (2009-12), Fløng-Hedehusene Fodbold (2012-16 and FC Roskilde (2016-18) before joining Brondby in May 2022. He made his professional debut on 17th July 2022 against AGF on the opening day of the Danish Superliga season aged 16 years and 71 days, becoming the youngest player in Brondby's history. He scored his first goal on 14th August 2006 becoming the second youngest goalscorer of all time in Superliga history.He played a total of 46 games for Brondby, scoring six goals including appearances in the Europa Conference League.

He has been capped by Denmark at Under-16, Under-17 and Under-19 levels.

He made his Norwich debut on 27th August 2024 in the English League Cup away at Crystal Palace.