Surtur or Saturn XLVIII (provisional designation S/2006 S 7) 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 and April 2006. It was named after Surt, a leader of the fire giants of Norse mythology. Surtur is about 4 kilometres in diameter, and orbits Saturn at an average distance of 22.707 Mm in 1297.7 days. The Surtian orbit is retrograde, at an inclination of 177.5° to the ecliptic and with an eccentricity of 0.451.