Nachi may refer to:
- National Association of Certified Home Inspectors
- A worm affecting Microsoft XP systems, also known as Welchia.
- A sacred area in Nachikatsuura, Wakayama, Japan. See Kumano Sanzan
- Nachi, a cruiser of the Imperial Japanese Navy, named after the place.
- The nickname for the Indian Pilot Kambampati Nachiketa, captured in the Kargil War.
- One of Bengal's most talented singer cum composer Nachiketa Chakroborty
- Nachi-Fujikoshi Corp . Manufacturer of Industrial equipment and bearings.