What is the name of the man who owns the Lego set in the live-action scenes?

The man who owns the Lego set in the live-action scenes is called The Man Upstairs.

The character is Finn’s father and the adult owner of the Lego collection around which the film’s real-world framing story is built. He keeps the set in a basement and treats the bricks as a carefully arranged collection rather than simply as toys for his son to change.

Inside the Lego world, Finn’s father is represented by Lord Business, the authoritarian businessman who wants to glue everything into a permanent, perfectly ordered design. The connection explains why the animated conflict mirrors the tension between a parent’s rules and a child’s imagination.

The film eventually shows that Finn’s father can understand the value of collaborative play. The name is a descriptive title rather than a conventional personal name, so “The Dad” may sound plausible but is not the character’s canonical designation. Will Ferrell portrays both The Man Upstairs and Lord Business.