Mathias Ullereng Kjølø (born 27 June 2001) is a Norwegian professional footballer who plays as a midfielder for Eredivisie club Twente.

[2] After six months with Vålerenga, he was sent on loan to Dutch Eredivisie club PSV Eindhoven, who then signed him to a permanent deal in 2018.

[2] He made his first-team debut for PSV on 8 November 2020 in a 3–0 domestic league win over Willem II, coming on as a substitute for Ibrahim Sangaré in the 88th minute.

[4] On 8 June 2022, PSV announced that Kjølø had signed a long-term contract to join FC Twente ahead of the 2022–23 season.

On 12 October 2021, he made his debut for the Norway national under-21 team in a 3–0 win over Estonia as a 78th-minute substitute for Johan Hove.