Depp stepped down from the role after losing his high-profile libel case against the Sun newspaper over an article that labelled him a “wife beater”. Previous reports suggested that Mikkelsen was director David Yates’ preferred choice to replace Depp, and was “in talks” to play Grindelwald.
Danish actor Mikkelsen, 55, rose to prominence as shady banker Le Chiffre opposite Daniel Craig in 2006 Bond film Casino Royale. He also played Dr Hannibal Lecter in the television series Hannibal.
In the Harry Potter universe, Grindelwald is an immensely powerful, evil wizard, who is regarded as second only to Voldemort.
Depp, 57, said he was asked to resign from the franchise by Warner Bros following his legal defeat. He was refused permission to appeal against the judgment, but has been given until 7 December to apply directly to the Court of Appeal.
Production on Fantastic Beasts 3 has been taking place in the UK, with Eddie Redmayne starring as Newt Scamander and Jude Law as Albus Dumbledore. The film is scheduled to be released on 15 July 2022.