Which company created the McDonald's advertising characters and world known as McDonaldland?

Needham Harper & Steers created the McDonald's advertising characters and world known as McDonaldland.

The Chicago advertising agency developed the fantasy setting and its early cast for McDonald's in the early 1970s. The campaign used recurring characters and locations to turn the restaurant brand into an imaginative world that could appear across television commercials and other marketing materials.

The agency is often confused with Leo Burnett, another major advertising firm that worked on important McDonald's campaigns and helped develop the familiar Ronald McDonald advertising identity. Those agencies had different roles in the brand's long advertising history.

McDonaldland became one of the most recognizable examples of character-based restaurant branding. It gave McDonald's a way to communicate with children through stories and visual symbols while keeping the restaurant's food and Golden Arches present in the background.