Lapp or LAPP may refer to:
- a now dated term for the Sami people
- Light art performance photography, a technique in the photography to emphasize landscapes, sceneries and objects with light. It's a symbiotic art between a performance with light and a shutter that's open for a long time
- The Laboratoire d'Annecy-le-Vieux de physique des particules, a French experimental physics laboratory located in Annecy-le-Vieux in the Savoie region of France
- A variation on the LAMP software stack
Lapp is a German surname that is common among the Amish and Mennonites, especially those of Lancaster County, Pennsylvania. It may refer to:
- Bernice Lapp (1917-2010), American Olympic swimmer
- Daniel Lapp, Canadian folk musician
- Henry Lapp (1862–1904), American carpenter-cabinetmaker
- Jack Lapp (1884–1920), American professional baseball player
- Katherine Lapp, administrator of Harvard University
- Ralph Lapp (c. 1910–2004), American physicist