McDonald's introduced “I'm Lovin' It” as a global slogan in 2003.
The campaign marked a shift toward one consistent international brand message. The phrase was designed to sound conversational and upbeat, while the accompanying “ba da ba ba ba” musical hook made it easy to recognize across advertising formats and languages.
The campaign was created through the German agency Heye & Partner and expanded internationally after its initial launch. Justin Timberlake appeared in an early campaign music video, but the slogan itself is McDonald's brand line rather than the title of a Timberlake song.
A common mistake is treating “I'm Lovin' It” as an older McDonald's slogan. It followed earlier campaigns such as “You Deserve a Break Today” and became the company's signature modern tagline.