| S/2020 S 4 | |
| Discovery Ref: |   |
| Discoverer: | Edward Ashton, Brett J. Gladman |
| Discovered: | 2020 |
| Eccentricity: | 0.495 |
| Period: | 2.538 yrs (926.96 d) |
| Inclination: | 40.1° |
| Satellite Of: | Saturn |
| Group: | Gallic group |
| Abs Magnitude: | 17.0 |
S/2020 S 4 is the faintest natural satellite of Saturn. It was discovered by Edward Ashton, Brett J. Gladman, Jean-Marc Petit and Mike Alexandersen on June 24, 2020, and was announced on May 6, 2023 by the IAU Minor Planet Center after observations were collected over a long period of time to confirm the satellite's orbit that were taken between July 1, 2019 and July 9, 2021.
S/2020 S 4 is a highly eccentric satellite with an eccentricity of 0.495, it orbits Saturn at an average distance of 18.2 million km and an orbital period of 2 and a half years, with an inclination of 40.1° to the ecliptic, suggesting that it belongs to the Gallic group. However, sometimes its moon group is disputed, and it may be included in the Inuit group. It has been suggested that it was a fragment piece of Siarnaq that broke off a long time ago in a time-span of a few thousand years.
The orbit of S/2020 S 4 is liberating in accordance of von Zeipel–Lidov–Kozai effect.
S/2020 S 4 is estimated to be 3 km in diameter and currently the faintest known moon of Saturn having an absolute magnitude of 17. Scott S. Sheppard and Tilmann Denk on the other hand, estimated it to be 2 km and 2 and a quarter km, respectively. If these estimates were true, it would make S/2020 S 4 one of the smallest known irregular moons of Saturn.