Sector 3, Sector III or variants may refer to:
Municipal sectors
edit- Sector 3 (Bucharest), an administrative sector of Bucharest, Romania
- A sector of Rohini Sub City, India
- A sector of Vashi, India
- Sector III, a neighbourhood in Getafe, Spain
Military sectors
edit- A sector of the United Nations Mission in Liberia
- A defence sector of the Bangladesh Armed Forces
Air traffic sectors
edit- Part of a holding pattern
- A sector of Anchorage Air Route Traffic Control Center coverage area
- A sector of London Area Control Centre coverage area
Other uses
edit- "Sector 3", a 1996 single by Ed Rush
- Sector3 Studios, a Swedish video game developer