McDonald’s launched “I’m Lovin’ It” in 2003 as its long-running global tagline.
The campaign was introduced internationally in September 2003 and was designed to give McDonald’s a more unified worldwide voice. Its wording used casual, contemporary language and focused on enjoyment rather than a specific menu item or restaurant feature.
The campaign is also associated with a song and advertising music performed by Justin Timberlake. The phrase was adapted across markets and languages while retaining the English slogan as the core global identity.
McDonald’s had used many earlier slogans, including “You Deserve a Break Today” and “We Love to See You Smile.” Those campaigns are important parts of the company’s advertising history, but they are not the answer to the 2003 global-tagline question.