Kristoffer Ajer

Start

He made his professional debut for Start on 19 July 2014 in a 2–1 win against Bodø/Glimt. At 16 years of age, Ajer captained Start in a 1–1 draw against Lillestrøm on 7 April 2015, becoming the youngest ever footballer to captain a team in the Tippeligaen. While playing for IK Start he played both as a central midfielder, but was gradually placed as a central defender.

Celtic

In early January 2016, Ajer had a one-week trial with Scottish club Celtic. On 17 February 2016, he signed a four-year contract with Celtic and joined the club in June 2016 for a fee which could rise up to £650,000. He was loaned to Kilmarnock in January 2017 and returned to his parent club to become a mainstay in central defence. On 14 May 2018, Ajer penned a new four-year deal with Celtic. On 30 August, Ajer scored his first goal for Celtic in a 3–0 win against FK Sūduva. On 24 October 2019, Ajer made his 100th appearance in all competitions for Celtic's first team in a Europa League match against Lazio.

Brentford

On 21 July 2021, Ajer completed a move to Premier League club Brentford on a five-year deal for an undisclosed fee. He made his Premier League debut on 13 August 2021 in a 2–0 win against Arsenal. He scored his first goal for Brentford against Southampton on 7 May 2022. On 21 November 2023, Ajer signed a new deal with Brentford until the summer of 2028, with the club keeping an option to extend his contract for a further season. He scored his second goal…

On 13 March 2018, Ajer received his first call-up to the Norwegian senior squad for friendly matches against Australia and Albania, debuting in the former match to honour his late grandfather. On 21 May 2026, Ajer was included in the 26-man squad selected by Norway national team manager Ståle Solbakken for the 2026 FIFA World Cup.

Club

As of match played 16 March 2026

International

As of match played 11 July 2026

Scores and results list Norway's goal tally first.

Kristoffer Vassbakk Ajer was born in Rælingen, Akershus County in Norway on 17 April 1998. In his younger years he participated in athletics, handball and ice hockey before ending up playing football. As a youth player he originally started his footballing career at Rælingen FK before joining Lillestrøm SK when he was eleven years old. He was eventually picked up by IK Start in 2014, which marked the start of his professional footballing career as a result of his parents moving to the city of Kristiansand on the Southern coast of Norway. While playing professionally for IK Start, he attended Kristiansand Katedralskole Gimle (High School) where he was known as a very conscientious and diligent student receiving a total of 18 straight A's. He attributed this to his strong competitive instinct and self-discipline, as well as the support from his teachers and parents and the fact that he values having a good education outside of his footballing career. Ajer originally planned enrolling at the Faculty of Medicine at the University of Oslo while simultaneously playing football professionally, but he has since put those plans on hold. On the reasons why he excelled as a footballer, he attributed this to his early physical development, strength and maturity:

I feel like I've been pretty lucky in my career. I was developing physically from a very early age: When I was six years old I was two heads taller than the rest of the players on the field. After a match where we won 30–0, I…