An old colleague of Jane Foster's father, Selvig is working with her to carry out her wormhole research, resulting in him being present when Thor arrives on Earth after his banishment. Having grown up with tales of the Viking myths, Selvig recognises Thor's 'stories', but assumes that they reflect a delusional mental state even after Jane's assistant speculates that the Norse gods could have been an advanced race who came to Earth. However, he and Thor bond after they spend the night drinking in a bar after he helped Thor escape S.H.I.E.L.D. custody, with Thor's identity being proven after Sif and the Warriors Three appear outside Jane's lab, followed by the Destroyer attacking the town and Thor reclaiming his hammer and powers.
In a post-credits scene, Selvig meets with Nick Fury and is offered the chance to study the Tesseract, but is already being observed and controlled by Loki.
Currently working for S.H.I.E.L.D. investigating the Tesseract, Selvig comes fully under Loki's control when Loki emerges from the portal generated by the Tesseract. He subsequently helps Loki devise a device that will allow him to generate a larger portal to bring in a mass invasion fleet to conquer Earth. Even when under Loki's control, Selvig is able to include a means of shutting the portal equipment down using Loki's staff, allowing him to inform Black Widow how to shut down the portal during the final battle. He is last seen standing with the Avengers as Thor takes Loki and the Tesseract back to Asgard.
