When Chris Hemsworth (Thor) and Sir Anthony Hopkins (Odin) saw each other in full armor for the first time, Hopkins said, "God, there's no acting required here, is there?"
The final choice for the role of Thor came down to brothers Chris Hemsworth and Liam Hemsworth. Chris found it funny: "We both came all the way over here from Australia and ended up battling against each other." He, however, bore no ill-will towards Liam, claiming he was rooting for him to get the role. This marked the second time two siblings vied for the same superhero role, after Alec Baldwin and William Baldwin were both considered to play Batman in Batman Forever (1995), but lost the part to Val Kilmer.
(at around 47 mins) Dr. Selvig (Stellan Skarsgård) mentions a comrade who got mixed up with S.H.I.E.L.D., whom he described as "a pioneer in gamma radiation." This alludes to Bruce Banner, whose experiments in gamma radiation mutated him into The Incredible Hulk (2008). A deleted scene also has him mention Hank Pym, from Ant-Man (2015).
(at around 28 mins) Director Sir Kenneth Branagh asked Sir Anthony Hopkins to improvise his reaction to Thor's yelling at him in the banishment scene. Hopkins agreed, and when the scene was filmed, many of the cast and crew present were sobbing. Chris Hemsworth and Tom Hiddleston later said they had to struggle to keep their composure during filming that scene. Hiddleston later complimented Hopkins, to which he said, "Ken's fantastic, isn't he?"
Executive producer Stan Lee claimed he'd always wanted to play Odin, but was happy with Sir Anthony Hopkins's casting and performance in the role.
J. Michael Straczynski: (at around 33 mins) A writer who worked on the "Thor" comics, appears as the first person to try to lift Mjölnir.
Stan Lee: (at around 36 mins) Executive producer and creator of Thor in 1962 appeared as the truck driver who attempts to tow Mjölnir out of the crater in which it landed.
Walter Simonson: (at around 1h 40 mins) A comic book writer and artist, whose work on "Thor" was highly renowned and acclaimed, has a cameo appearance in the banquet scene near the end of the movie, sitting between Sif (Jaimie Alexander) and Volstagg (Ray Stevenson).