Which German advertising agency originated McDonald's “I'm lovin' it” campaign concept?

Heye & Partner originated the concept for McDonald's “I'm lovin' it” campaign.

The German agency developed the campaign idea that McDonald's adopted for a major worldwide marketing effort in 2003. The campaign was notable because McDonald's used one central identity across many countries, while local markets adapted executions and language.

DDB Chicago is often associated with the campaign because it handled important creative and advertising work for McDonald's in the United States. However, Heye & Partner is credited with originating the concept, making the two agencies easy to confuse.

The campaign also used a musical hook performed by Justin Timberlake and produced by the Neptunes. Its short English slogan became a durable part of McDonald's international branding.