Which McDonald's character was the head of state in the McDonaldland advertising world?

Mayor McCheese was the head-of-state character in McDonaldland advertising.

McDonaldland was a fictional setting created for McDonald's advertising in the early 1970s. Mayor McCheese appeared as a human mayor with an oversized cheeseburger for a head, combining civic imagery with the restaurant’s food branding. He was one of several characters used to make McDonald's advertising resemble a colorful children's fantasy world.

Mayor McCheese is sometimes confused with Ronald McDonald, who was the central mascot and host of the setting. Other characters, including the Hamburglar and Grimace, had different roles and personalities. The character’s design was also involved in a copyright dispute with the creators of the television program H.R. Pufnstuf; a court found substantial similarity between parts of the concepts.

McDonaldland characters gradually became less prominent in national advertising, but Mayor McCheese remains a distinctive example of the chain’s early character branding.