The fictional world introduced by McDonald's in 1971 was McDonaldland.
McDonaldland gave the company a shared setting for television commercials, restaurant playgrounds, promotional products, and children's marketing. Its characters included Ronald McDonald, the Hamburglar, Grimace, Mayor McCheese, and Birdie the Early Bird.
The setting turned menu items and restaurant features into a colorful story world. That approach made McDonald's branding especially memorable to children and gave the company recurring characters instead of relying only on food photography or price messages.
McDonaldland characters changed over time, and not all appeared in every market or period. The name should not be confused with the separate McDonald's PlayPlace concept, which refers to restaurant play areas rather than the fictional advertising universe.