ARIEL 4
| Launched | 10 December 1971 |
| Flight ended | 11 December 1978 |
| Status | Decayed |
| Launch site | Air Force Western Test Range, California, USA |
| Owner | United Kingdom |
| NORAD ID | 5675 |
| COSPAR ID | 1971-109A |
| Alternative names |
UK-4 |
| Observing |