4 Squadron
- 2/4th Cavalry Commando Squadron (Australia)
- 4 Squadron SAAF
- 4th Aero Squadron
- 4th Battle Squadron (United Kingdom)
- 4th Fighter Squadron (United States)
- 4th Space Control Squadron (United States)
- 4th Space Operations Squadron (United States)
- 4th Submarine Squadron (United Kingdom)
- HS-4
- No. 4 Squadron (India)
- No. 4 Squadron RAAF
- No. 4 Squadron RNZAF
- No. IV Squadron RAF
- Submarine Squadron 4 (United States)
- VMAQ-4