Chris Hemsworth's family appears in this film:
- Sons Sasha Hemsworth and Tristan Hemsworth play young Thor (at different ages).
- Daughter India Rose Hemsworth plays Gorr's daughter.
- Brother Luke Hemsworth plays a stage actor portraying Thor.
- Wife Elsa Pataky plays a former lover of Thor (the wolf woman in the opening sequence).
Christian Bale had initially turned down the possibility of appearing in any more comic book or superhero films after Batman: El caballero de la noche asciende (2012), seeing the genre as uninteresting from an acting perspective, and especially finding the experience of donning the Batman costume to be a miserable one. He agreed to take part in this film however, having been impressed by Taika Waititi's previous works and after his kids begged him to take the role.
Natalie Portman told In a Total Film in a separate interview that Christian Bale looked terrifying while in costume. "The children would run screaming," she said. "He has a very, very, very scary look, in addition to, of course, his excellent acting. But, on this one, in between, he'd be like, 'Hey, what's up?' It was just a normal conversation, which was jarring, because he looked terrifying."
(at around 54 mins) Korg's god Ninny-Nonny sits on a throne of scissors because in the Rock-Paper-Scissors game rock beats scissors.
It was Russell Crowe's idea to have Zeus speak with a Greek accent. Director Taika Waititi wanted a British accent for the Greek god, so he had Crowe do every take once in the Greek accent and once with a British accent. Waititi then determined that Crowe was right, and the Greek accent worked best.