2010 WG9

 is a high inclination trans-Neptunian object and slow rotator from the outer Solar System, approximately 100 kilometers in diameter. It was first observed at ESO's La Silla Observatory in northern Chile on 30 November 2010.

Orbit and classification
orbits the Sun at a distance of 18.8–87.0 AU once every 384 years and 9 months (140,538 days). Its orbit has an eccentricity of 0.65 and an inclination of 70° with respect to the ecliptic.

As of October 2019, it is one of six known objects with inclination (i) > 60° and perihelion (q) > 15 AU, along with the first discovered.

Rotation period
A rotational lightcurve of was obtained from photometric observations by the LaSilla–Quest Variability Survey at La Silla in Chile. Lightcurve analysis gave a rotation period of 263.8 hours with a brightness amplitude of 0.14 magnitude (U=2). It belongs to the Top 200 slowest rotators known to exist.

Diameter and albedo
It measures 112.7 kilometers in diameter and its surface has an albedo of 0.074. The Collaborative Asteroid Lightcurve Link assumes a standard albedo of 0.10 and calculates a diameter of 100.81 kilometers based on an absolute magnitude of 8.1.