McDonaldland was the name of McDonald's fictional advertising universe populated by Ronald McDonald and other characters.
The campaign presented the restaurant's branding as a colorful fantasy setting for children. Characters represented different products or playful ideas, making the advertising world easy to recognize across television commercials, restaurant decorations, and promotional materials.
Ronald McDonald was the central character, while figures such as the Hamburglar, Grimace, and Mayor McCheese occupied supporting roles. Their designs and uses changed over the years, which is why individual character debut dates are sometimes confused.
McDonaldland was especially prominent from the 1960s through the 1980s. It was an advertising creation rather than a real place, and its name should not be confused with the McDonald's restaurant chain itself.