Jannik Vestergaard (born 3 August 1992) is a Danish professional footballer who plays as a centre back for Premier League club Southampton, and for the Danish national team.
Vestergaard played youth football with Vestia, Frem, Copenhagen and Brøndby. He began his senior career with German club TSG 1899 Hoffenheim. He moved to Werder Bremen in January 2015.
On 11 June 2016, Vestergaard joined Borussia Mönchengladbach for a reported transfer of €12 million plus bonuses.
Vestergaard moved to English club Southampton on 13 July 2018, signing a four-year contract. On 12 August 2018, he made his debut in a 0-0 draw against Burnley in the Premier League. He scored his first goal for the club on 31 August 2019, the equalizer in a 1–1 draw against Manchester United.