Leppä is a Finnish surname of Laine type literally meaning "alder". Notable people with the surname include:
- Aleksi Leppä
- Henry Leppä
- Jari Leppä, Finnish politician
- Jouko Leppä, Finnish Olympic weightlifter
- Juhani Leppä , Finnish politician
- Leo Leppä
- Perttu Leppä (born 1964), Finnish film director and writer
- Sulho Leppä (1878–1918), Finnish politician