(91205) 1998 US43

' (provisional designation ') is a resonant trans-Neptunian object of the plutino group, located in the Kuiper belt in the outermost region of the Solar System. The rather bluish body measures approximately 111 km in diameter. It was discovered on 22 October 1998, by American astronomer Marc Buie at the Kitt Peak National Observatory in the United States. It is probably not a dwarf planet candidate.

Classification and orbit
belongs to the plutino population, a large population of resonant trans-Neptunian objects named after the group's largest member, Pluto. Thus, is in a 2:3 orbital resonance with Neptune, orbiting the Sun twice for every three times Neptune does.

It orbits the Sun with a semi-major axis of 39.06 AU, a perihelion of 33.9 AU, and an aphelion of 44.2 AU, completing an orbit once every 244 years and 2 months (89,179 days). Its orbit has an eccentricity of 0.13 and an inclination of 11° with respect to the ecliptic. The body's observation arc begins with its official discovery observation. Its orbit still has a fair amount of uncertainty.

Numbering and naming
This minor planet was numbered by the Minor Planet Center on 28 October 2004 (M.P.C. 52912). As of 2018, it has not been named.

Physical characteristics
Based on an absolute magnitude of 8.0 and an assumed albedo of 0.09, the Johnston's Archive estimates a diameter of 111 kilometers. The body's spectrum (BB–BR) suggests a somewhat bluish color. As of 2018, no rotational lightcurve of has been obtained from photometric observations. it an unlikely dwarf planet candidate due to its small size, estimated by Michael Brown to measure 154 kilometers with a low albedo of 0.04.