| Jarnsaxa | |
| Mpc Name: | Saturn L |
| Alt Names: | S/2006 S 6 |
| Discoverer: | Scott S. Sheppard David C. Jewitt Jan T. Kleyna Brian G. Marsden |
| Discovered: | June 26, 2006 |
| Named After: | Járnsaxa |
| Orbit Ref: | [1] |
| Inclination: | 163.3° |
| Eccentricity: | 0.216 |
| Period: | −964.7 days |
| Satellite Of: | Saturn |
| Group: | Norse group |
| Physical Ref: | [2] |
| Mean Diameter: | 4 km |
| Albedo: | 0.06 (assumed) |
| Magnitude: | 24.7 |
| Abs Magnitude: | 15.6 |
Jarnsaxa, also known as Saturn L (provisional designation S/2006 S 6), is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on June 26, 2006, from observations taken between January 5 and April 29, 2006.
Jarnsaxa is about 4 kilometres in diameter, and orbits Saturn at an average distance of 18,556.9 Mm in 943.784 days, at an inclination of 162.9° to the ecliptic (164.1° to Saturn's equator), in a retrograde direction and with an eccentricity of 0.1918. It is a member of the Norse group of irregular satellites.
It is named after Járnsaxa, a giantess in Norse mythology.