Rocky IV marked Dolph Lundgren's debut in what kind of film?

Rocky IV marked Dolph Lundgren's American film debut.

Lundgren had a background in martial arts and had worked as a bodyguard before being cast as Ivan Drago, the imposing Soviet boxer opposite Sylvester Stallone. Rocky IV introduced him to American movie audiences and became the breakthrough role that launched his long career in action cinema.

The wording matters: Rocky IV was Lundgren's American film debut, not a reference to documentary, silent, or Swedish film. “Swedish film” is a tempting choice because Lundgren is Swedish, but the production is an American sports drama made within the Rocky franchise. His nationality describes the actor and Drago's fictional identity, not the category asked for in the question.

The film was released in 1985 and also featured Brigitte Nielsen as Drago's wife, Ludmilla. Lundgren later returned as Ivan Drago in Creed II, connecting his debut role to a new generation of Rocky stories more than three decades later.