(15874) 1996 TL₆₆ (provisional designation 1996 TL₆₆) is a trans-Neptunian object of the scattered disc orbiting in the outermost region of the Solar System.^[2][3]

The Spitzer Space Telescope has estimated this object to be about 575 kilometres (357 mi) in diameter,^[6] but 2012 estimates from the Herschel Space Observatory estimate the diameter as closer to 339 kilometres (211 mi).^[5] It is not a detached object, since its perihelion (closest approach to the Sun) is under the influence of Neptune.^[3] Light-curve-amplitude analysis suggests that it is a spheroid.^[9] Tancredi presents "in the form of a decision tree, the set of questions to be considered in order to classify an object as an icy 'dwarf planet'." They find that (15874) 1996 TL₆₆ is very probably a dwarf planet.^[10] Mike Brown's website, using a radiometrically determined diameter of 344 kilometres (214 mi), lists it as a possible dwarf planet.^[11]

Discovered in 1996 by David C. Jewitt et al., it was the first object to be categorized as a scattered-disk object (SDO), although (48639) 1995 TL8, discovered a year earlier, was later recognised as a scattered-disk object. It was considered one the largest known trans-Neptunian objects at the time of the discovery, being placed second after Pluto.^[12] It came to perihelion in 2001.^[2]

(15874) 1996 TL₆₆ orbits the Sun with a semi-major axis of 83.9 AU^[2] but is currently only 35 AU from the Sun with an apparent magnitude of 21.^[8] In 2007, the Spitzer Space Telescope estimated it to have a low albedo with a diameter of about 575±115 km.^[6] More-recent measurements in 2012 by the 'TNOs are Cool' research project and reanalysis of older data have resulted in a new estimate of these figures.^[5] It is now assumed that it has a higher albedo and the diameter was revised downward to 339±20 km. Light-curve-amplitude analysis shows only small deviations, suggesting (15874) 1996 TL₆₆ is a spheroid with small albedo spots and may be a dwarf planet.^[9]