“I'm Lovin' It” became McDonald's worldwide advertising tagline after its 2003 campaign launch.
McDonald's introduced the campaign in Munich, Germany, in September 2003, then rolled it out internationally. The wording used a deliberately conversational form rather than the more formal “I love it,” giving the campaign a casual, youthful tone.
The campaign also used a musical identity associated with the phrase. Justin Timberlake recorded a vocal version of the jingle, while the production and later advertisements helped make the five-note motif strongly associated with McDonald's.
The slogan is sometimes confused with earlier McDonald's taglines, especially “You Deserve a Break Today,” which was a major campaign from the 1970s. “I'm Lovin' It” succeeded those earlier slogans and became the long-running global platform rather than a short regional promotion.