Which advertising agency created McDonald's slogan and campaign phrase “I'm lovin' it”?

Heye & Partner created McDonald's “I'm lovin' it” slogan and campaign phrase.

McDonald's launched the global “I'm lovin' it” campaign in 2003. The phrase was unusual because it used informal, conversational wording and a deliberately nonstandard contraction, making the line sound like spoken language rather than a formal corporate statement.

The campaign originated through the German agency Heye & Partner and was then adapted for worldwide use. Justin Timberlake appeared in an early campaign-related recording, while the musical hook helped the phrase travel across markets and media formats.

The slogan is often associated with the “ba da ba ba ba” musical tag, but the tagline and the music are not the same thing. McDonald's retained the phrase for many years, making it one of the company's longest-running modern branding platforms.