Nijssen is a Dutch patronymic surname originating from the given name "Denijs" (Denis).[1] People with this surname include:
- Nijssen
- Han Nijssen (1935–2013), Dutch ichthyologist
- Sjir Nijssen (born 1938), Dutch computer scientist known for Nijssen's Information Analysis Method
- Tom Nijssen (born 1964), Dutch tennis player
- Nyssen
- Hubert Nyssen (1925–2011), Belgian writer and publisher