McDonaldland was the fictional advertising world populated by Ronald McDonald, Mayor McCheese, and other McDonald's characters.
The setting gave the company a shared environment for its television commercials and promotional material. Rather than presenting each mascot in isolation, McDonaldland connected them through recurring locations, roles, and stories. This made the advertising easier for children to recognize and gave McDonald's a distinctive fantasy identity.
The cast included characters whose designs referenced McDonald's products or restaurant imagery. Mayor McCheese had a cheeseburger-shaped head, while other figures included the Hamburglar, Grimace, and Officer Big Mac. Ronald McDonald served as the central human-like host of the world.
McDonaldland is a brand-world name, not the name of a restaurant chain or a real place. It is also distinct from “McDonald's,” the corporate and restaurant brand itself. The fictional setting belongs specifically to the company's character-based advertising history.