Who performed the vocal version of McDonald's “I'm Lovin' It” theme in the 2003 campaign?

Justin Timberlake performed the vocal version of McDonald's “I'm Lovin' It” theme in the 2003 campaign.

The campaign used music as a central branding device rather than treating the slogan as only a spoken advertising line. Timberlake recorded the vocal track associated with the theme, helping give the phrase a recognizable pop-music identity.

The campaign's music was connected to the “I'm Lovin' It” branding and appeared alongside McDonald's advertising in multiple markets. Its use of a contemporary recording artist helped the company target younger audiences while keeping the slogan easy to remember.

A common mix-up is crediting one person with every part of the campaign. The advertising concept, production, songwriting, and performance involved different contributors; Timberlake is the credited vocalist associated with the released theme.