McDonald's first major advertising mascot was Speedee.
Speedee represented the fast-service idea behind the original McDonald's restaurant system. He was commonly depicted as a smiling chef and was used in signs, packaging, and other early promotional material. His name was a direct reference to the speed of food preparation.
Speedee later disappeared from the central role as McDonald's advertising became more character-driven. Ronald McDonald became the principal mascot in the 1960s, while the fictional McDonaldland characters added a larger story world in later decades. Because of that change, some people incorrectly assume Ronald was the brand's first mascot.