McDonald's introduced the global tagline “I'm Lovin' It” in 2003, following “We Love to See You Smile.”
The phrase was launched as part of a major worldwide branding campaign designed to give McDonald's a more unified voice across markets. Its casual wording and use of the first-person expression made it easy to adapt in advertising and everyday conversation.
The campaign included a music-based identity associated with a jingle and a song performed by Justin Timberlake. McDonald's advertising used the phrase in many countries, sometimes alongside locally adapted material while retaining the English tagline.
The earlier line “We Love to See You Smile” dates from the 1990s, while “You Deserve a Break Today” belongs to the 1970s. These slogans are often remembered together because each occupied a prominent period in McDonald's advertising history.