“I'm Lovin' It” was McDonald's global advertising campaign launched in 2003 and associated with a five-note vocal hook.
The campaign was introduced internationally and became the first McDonald's advertising theme used consistently across many countries. Its short slogan and musical signature were designed to work across languages and markets.
The campaign's musical development involved several performers and producers, which has led to frequent arguments about who should receive sole credit for the jingle. The branding fact is clearer than the authorship debate: McDonald's adopted “I'm Lovin' It” as its global campaign in 2003.
The slogan replaced neither every local phrase nor every advertisement immediately. McDonald's markets could still adapt executions and languages, but the central wording and hook created a more unified worldwide identity than many earlier campaigns.