The Professor was the scientist and inventor in the original McDonaldland cast.
McDonald's used The Professor as an adult character who explained inventions, gadgets, and unusual events in the fictional advertising world. His role contrasted with the more food-centered or mischievous figures surrounding him.
The character belonged to the McDonaldland ensemble introduced in the early 1970s. That ensemble gave McDonald's commercials recurring settings and personalities, allowing the brand to build stories rather than rely only on product demonstrations.
The Professor is sometimes mistaken for a generic narrator or for another adult McDonaldland character. His defining branding function was his inventor identity. Mayor McCheese represented civic leadership, Officer Big Mac represented law enforcement, and The Professor represented technical knowledge.