The 18-year-old had been heavily linked with a move to Premier League sides Newcastle United but has been officially unveiled by the Seagulls ahead of the 2026/27 campaign.
"Ignore the noise, it was always Brighton," said the teenager in a video on the club's social media.
According to media reports, Brighton are set to pay a 21.5million pound fee for the attacker after signing a five-year-deal with the club.
Yohanna impressed last season with AIK, scoring five goals and providing four assists in 12 appearances in all competition as his former club narrowly missed out on the Allsvenskan title to Malmo.
He is set to compete with Yankuba Minteh on the right side of attack.
Federico Chiesa has confirmed he is ready to hold talks over his future at Liverpool after revealing he will meet new head coach Andoni Iraola to decide whether he remains at Anfield next season.
Nick Woltemade has insisted that his first season at Newcastle United has given him the ideal preparation for the 2026 FIFA World Cup, even after admitting he went through a difficult spell in form during the campaign.
Chelsea forward Estevao has revealed he is close to making a return to action after recovering faster than expected from the serious hamstring injury that ended his hopes of playing for Brazil at the 2026 FIFA World Cup.
Andy Robertson has described his call-up to Scotland's 2026 World Cup squad as a "huge pinch yourself moment" after being named in Steve Clarke's 26-man group for football's biggest tournament.
