(78799) 2002 XW₉₃, provisional designation 2002 XW₉₃, is a trans-Neptunian object and centaur from the outer Solar System, approximately 500–600 kilometers (300–400 mi) in diameter. It was discovered on 10 December 2002, by astronomers at the Palomar Observatory in California.^[1]

2002 XW₉₃ orbits the Sun at a distance of 27.9–46.8 AU once every 228 years and 4 months (83,410 days; semi-major axis of 37.36 AU). Its orbit has an eccentricity of 0.25 and an inclination of 14° with respect to the ecliptic.^[2] The body's observation arc begins with a precovery published by the Digitized Sky Survey and taken Palomar in December 1989, or 13 years prior to its official discovery observation.^[1]

As of 2016, after a total of 29 observations, its orbital uncertainty parameter is at 3. Its last observation was made by the Hubble Space Telescope in September 2008.^[1] On 10 August 1926, it most recently reached perihelion, when it was nearest to the Sun.^[6][1] It is a near 5:7 resonant trans-Neptunian object.^{[citation needed]}

This minor planet was numbered by the Minor Planet Center on 15 April 2004.^[7] As of 2023, it has not been named.^[1]