“I'm Lovin' It” became McDonald's global tagline in 2003 through a campaign built around the same phrase and song.
The campaign was developed for McDonald's by the advertising agency Heye & Partner and rolled out internationally. Its musical identity helped the phrase work across markets and made it one of the most recognizable modern elements of McDonald's branding.
The campaign is sometimes associated only with the pop recording used in advertisements, but the phrase itself is the central brand tagline. It also should not be confused with the older slogan “You Deserve a Break Today,” which McDonald's introduced in 1971.
Unlike many earlier campaigns that were strongly tied to a particular era or market, “I'm Lovin' It” was designed as a global platform and has remained closely connected with McDonald's branding.