Which McDonald's advertising slogan began its major campaign in 2003?

“I'm Lovin' It” began its major McDonald's advertising campaign in 2003.

McDonald's introduced the campaign internationally in 2003 as part of an effort to give the company a more unified, upbeat identity. The slogan was presented in lowercase styling and paired with the familiar “ba da ba ba ba” musical phrase. It became one of the most recognizable elements of the chain's modern branding.

The campaign was created through advertising work associated with Heye & Partner and the global marketing network. The music and phrase were adapted for markets around the world, while translations and local executions varied.

The slogan is sometimes confused with earlier McDonald's campaigns such as “You Deserve a Break Today,” which dates from the 1970s. “I'm Lovin' It” belongs to the 21st-century brand era and remained closely associated with McDonald's advertising afterward.