The Premier League club will pay 30 million euros ($33.56 million) in guaranteed payments with an additional 5 million euros in performance-related add-ons, Fenerbahce said on Public Disclosure Platform (KAP), while Brighton also confirmed the deal on social media platform X.
The 24-year-old defender, who joined Fenerbahce in 2018, has a Turkish father and a Dutch-Canadian mother and played up to under-21 level for the Netherlands before switching his allegiance to Turkey in 2022.
He was a stand-out player for Turkey in their 2-1 win over Austria in the last 16 of this year's European Championship.
Jose Mourinho-coached Fenerbahce, who were runners-up in last season's Turkish Super Lig, added that they would receive 10% of any future transfer fee that Brighton received for the player.
Kadioglu's transfer equals the Super Lig record held by French defender Sacha Boey, who moved from champions Galatasaray to Bayern Munich for 30 million euros ($32.85 million) in January.
