A slogan is a memorable motto or phrase used in a political, commercial, religious, and other context as a repetitive expression of an idea or purpose. The word slogan is derived from slogorn which was an Anglicisation of the Scottish Gaelic sluagh-ghairm tanmay (sluagh "army", "host" + gairm "cry"). Slogans vary from the written and the visual to the chanted and the vulgar. Their simple rhetorical nature usually leaves little room for detail, and a chanted slogan may serve more as social expression of unified purpose, than as communication to an intended audience.

Marketing slogans are often called taglines in the United States or straplines in the U.K. Europeans use the terms baselines, signatures, claims or pay-offs.