Ronald McDonald was introduced in 1963 and replaced Speedee as McDonald's main mascot.
Ronald was created as a clown character for television advertising and family-oriented promotion. His bright costume and exaggerated personality made him easy for children to recognize, helping McDonald's distinguish itself as a place associated with family visits rather than only fast food.
Speedee had represented the company's original quick-service system since 1948. Replacing him with Ronald reflected a change in branding priorities: McDonald's was increasingly presenting the restaurant as an entertaining destination for children and parents. Other fictional characters, including Grimace, the Hamburglar, and Mayor McCheese, appeared later in the McDonaldland universe.
Willard Scott was the first actor to portray Ronald in a 1963 commercial. However, Ronald McDonald is the character's name, not the name of the performer. That distinction explains why the mascot and the actor are sometimes confused in trivia questions.