WIII may refer to:
- Soekarno–Hatta International Airport (ICAO code "WIII") in Jakarta, Indonesia
- WIII (FM) 99.9, a radio station in Cortland, New York, United States
- WSTR-TV, whose former calls were WIII, in Cincinnati, Ohio, United States
WIII (branded as I-100) is a radio station serving the vicinity of Ithaca and Cortland, New York, with a classic rock format. This station broadcasts at 99.9 MHz in Cortland and 100.3 MHz (via translator W262AD) in Ithaca. It is owned by Saga Communications.