Kristoffer Ajer has made the switch to Premier League newcomers Brentford from Celtic for an undisclosed fee, the Bees have confirmed.
Ajer completed a medical before signing a five-year contract, with the deal subject to international clearance.
The 23-year-old joined Celtic shortly after his 18th birthday and spent the second half of his first year in Scotland on loan at Kilmarnock before becoming a first-team regular.
Brentford head coach Thomas Frank said: “We wanted to get another central defender in and Kris was our first choice. We think he fits the position-specific profile perfectly, especially on the ball.
“Kris is very composed and can find the right passes between the lines. His level when bringing the ball forward is very high.
“As a defender he has the physicality that you need and he won his duels when he played in the Scottish league. He can help us in both boxes, with his strength in the air.
“He is a player at a good age and we think he (can) come straight in and be ready to perform in the Premier League. But he also fits the way we want to recruit players and work with them. He can develop as a player and both Brentford FC and Kris can move to a higher level in the coming years.”