(278361) 2007 JJ43

 is a large trans-Neptunian object (TNO) orbiting the Sun near the outer edge of the Kuiper belt. Its discovery images were taken in 2007, and its absolute magnitude of 4.5 is one of the twenty brightest exhibited by TNOs. Assuming it has a typical albedo, this would make it roughly the same size as Ixion (about 530–620 km diameter). In a paper in the Astrophysical Journal Letters András Pál and colleagues estimate a diameter for of $278,361$.

Observations by Brown in 2012, using the W. M. Keck Observatory, suggest that does not have a companion.

, it is about 41.3 AU from the Sun.