Niilo is a male given name. People named Niilo include:
- Niilo Wälläri (1897–1967), Finnish Socialist, syndicalist leader
- Niilo Yli-Vainio (1920–1981), Finnish Pentecostalist leader
- Niilo Halonen (born 1940), Finnish former ski jumper who competed between 1960 and 1967
- Niilo Paasivirta, Finnish internet personality
- Niilo Jääskinen (born 1958), Finnish lawyer and politician
- Niilo Sevänen (born 1979), Finnish death metal musician
- As a surname
- Tiit Niilo (born 1962), Estonian politician
See also
- 2972 Niilo (1939 TB), a Main-belt Asteroid discovered in 1939