McDonald's introduced its famous “I'm Lovin' It” slogan in 2003.
The campaign was launched internationally as a major effort to give McDonald's a single, contemporary advertising platform across markets. The slogan was paired with a five-note musical signature that became closely associated with the brand.
The campaign is sometimes linked exclusively with Justin Timberlake because he appeared in an early related advertisement and recorded a version of the song. However, the slogan and campaign were McDonald's corporate branding, not the title of a Timberlake album or a restaurant product.
“I'm Lovin' It” replaced a succession of earlier McDonald's advertising lines and remained central to the company's global marketing. Its wording was deliberately conversational and positive, allowing local advertising teams to adapt the surrounding material while retaining a common international identity.