McDonald's introduced “I'm Lovin' It” as its internationally famous tagline in 2003.
The campaign began in Munich, Germany, in 2003 and was later rolled out globally. It was the first McDonald's advertising campaign designed for worldwide use under one central slogan and musical identity.
The phrase was paired with a distinctive five-note audio signature, often called the “ba da ba ba ba” jingle. Justin Timberlake appeared in an early campaign advertisement, while the campaign's music was associated with producer Pharrell Williams.
The slogan is sometimes attributed entirely to a celebrity because of the campaign's music and performers. In fact, it was a McDonald's global advertising platform developed through agency work and adapted across markets. Earlier slogans remained important parts of the company's advertising history.