Schlapp is the surname of:
- Alyce Louise Schlapp (1912–1999), American politician
- George E. Schlapp (1839–1912), American brewer
- Lothar Schlapp (1960), former professional German footballer
- Matt Schlapp (1967), American political activist and lobbyist
- Mercedes Schlapp (1972), American communications specialist and political commentator
- Robert Schlapp (1899–1991), British physicist and mathematician of German descent