| Janet Gillies | |
| Birth Date: | 31 January 1864 |
| Birth Place: | Whanganui, New Zealand |
| Death Place: | Auckland, New Zealand |
| Allegiance: | United Kingdom New Zealand |
| Branch: | British Army (1900–02) New Zealand Military Forces (1908–10) |
| Serviceyears: | 1900–1902 1908–1910 |
| Rank: | Matron-in-Chief |
| Commands: | New Zealand Medical Corps Nursing Reserve (1908–10) |
| Battles: | Second Boer War |
Janet Gillies (31 January 1864 – 24 July 1947) was a New Zealand civilian and military nurse, army nursing administrator. She was born in Whanganui, New Zealand, on 31 January 1864. Between 1899 and 1902 she served as a nurse in the Second Boer War. She was awarded the King's South Africa Medal. After returning to New Zealand, she became an advocate for the establishment of the New Zealand Army Nursing Service.