The fictional world introduced for McDonald's advertising characters in 1971 was called McDonaldland.
McDonaldland gave McDonald's characters a shared setting and helped turn restaurant advertising into an interconnected fantasy world. Ronald McDonald appeared with characters such as Mayor McCheese, Grimace, the Hamburglar, and Birdie the Early Bird. The setting made the brand easier for children to recognize across television commercials, restaurant displays, packaging, and promotions.
McDonaldland is sometimes mistaken for the name of a single restaurant concept or a menu line. It was instead a fictional advertising environment. The characters' designs and roles changed over time, and several were later used less prominently as McDonald's marketing strategy evolved.
The 1971 date refers to the introduction of the advertising world, not to the founding of McDonald's itself. The original restaurant business began earlier, while McDonaldland represented a later phase of the company's family-oriented branding.