Yohanna, 18, has signed a five-year contract with Brighton running until June 2031. The move will be completed when the summer transfer window officially opens on June 15.
The teenager joined AIK from Ikon Allah Football Academy in Nigeria in 2025 and made an immediate impact, scoring five goals in 18 appearances and drawing scouts from across the continent. According to one report, 32 European scouts attended a single AIK fixture specifically to observe him.
Brighton head coach Fabian Hurzeler spoke directly with Yohanna before the deal was agreed.
"I'm looking forward to working with Zadok," Hurzeler said. "Having seen his games and his attributes, he is a player that can impact games in the final third.
"He's still young, and will need time to adapt to the club and Premier League, but he's an exciting player to watch and he brings the kind of creativity we know our fans will enjoy."
Newcastle United submitted a bid worth up to €30 million according to multiple reports. Chelsea also entered the race, with the Daily Mail reporting that AIK accepted offers from both clubs in the region of £21 million.
According to Expressen, a Saudi club — Al-Qadsiah — matched Brighton's total package and was willing to pay the full amount immediately, while also tabling a lucrative personal contract for the player.
Yohanna declined the Saudi approach.
Chelsea's interest reportedly fell away as their negotiations extended, with the Swedish publication reporting they were not involved at the decisive stage of the process.
Brighton's track record in unearthing and developing young talent from non-traditional markets was a significant factor in Yohanna's decision. The club's development pathway, combined with Hurzeler's direct communication, proved more persuasive than raw financial competition.
Yohanna received his first call-up to the Nigeria senior national team earlier in the year, though AIK did not release him due to a hamstring injury at the time.
The fee breaks the previous record for a sale by a Swedish club and provides a return on a player who cost AIK nothing when recruited from Nigeria twelve months ago.