Justin Timberlake was featured on the original 2003 recording associated with McDonald's “I'm Lovin' It” campaign.
The campaign's musical identity grew from a song created by the German production team Mona Davis and later developed for McDonald's advertising. Timberlake recorded vocals for the track, and the resulting music helped the tagline travel beyond a printed slogan. The campaign was launched internationally in 2003.
The branding credit can be confusing because several artists and producers have been connected with versions, remixes, and later uses of the “ba da ba ba ba” hook. Timberlake's association is with the original campaign-era recording, not with ownership of the slogan itself.
McDonald's used the phrase and melody across television, radio, online advertising, and in-store materials. That broad repetition made the musical signature as recognizable as the Golden Arches for a later generation.