From Longman Dictionary of Contemporary Englishheadlinerhead‧lin‧er /ˈhedlaɪnə $ -ər/ noun [countable] the main performer or band in a concert
Examples from the Corpus
headliner• David had come to the United States as a headliner.• The eventual headliners, believe it or not, were Mud.• Meadowbrook I knew all about, a steady ensemble man but no headliner.• It feels good to be the headliner.• As often seems the case these days, the opening acts are of more interest than the headliner. 