Strictly speaking, a mummer is an actor in a traditional seasonal folk play. The term is also humorously (or derogatorily) applied to any actor.
Mummer may also refer to: A mummer, costume-wearing celebrant from medieval to early-modern times A participant in the New Year's Day Mummers Parade in Philadelphia, USA, and other similar festivals A participant in the Newfoundland and Labrador Christmas time celebration based on the Irish tradition of mummering A participant in Mummer's Day, a midwinter celebration in Padstow, Cornwall, UK A mime artist, one acting out a story through body motions, without use of speech A member of the Summer Mummers theatre group in Midland, Texas, USA MUMmer, a bioinformatics software system Mummer (album), a 1983 album by the group XTC The Mummers, a band based in Brighton, England