Media information about the lending has circulated for a long time.
AIK writes on its website that Viktor Fischer will immediately join the club's ongoing training camp in Portugal.
"I'm looking forward to being part of a club that has really shown in recent weeks that they want me to be part of their 2023 season," Fischer said in a statement.
The 28-year-old has played 21 A international matches for Denmark and scored three goals in the national team shirt.
He broke through in Ajax as a junior and promising talent in 2011 and was involved in winning the league title with Ajax in the 2012/2013 and 2013/2014 seasons.
Modest with playing time
After three and a half years at FC Copenhagen, Fischer signed a four-year contract with Royal Antwerp FC in the 2021 summer window.
In the past year, he has not been a given starting player in the Belgian club as he has been pulled with injury concerns.
During the current season, he has received modest playing time.
- If he can get back to his old good match form, he could potentially become this year's exclamation point in the Allsvenskan, says AIK CEO Manuel Lindberg.