Bortnik (Belarusian: Бортнік, Ukrainian: Бортник, Bortnyk) is a Belarusian and Ukrainian surname. The historical meaning of the surname is beekeeper. Notable people with the surname include:
- Aída Bortnik (1938–2013), Argentine screenwriter
- Bogdan Bortnik (born 1992), Ukrainian footballer
- Ivan Bortnik (1939–2019), Russian actor