Chadwick A. Trujillo (born November 22, 1973) is an American astronomer, discoverer of minor planets and the co-discoverer of Eris, the most massive dwarf planet known in the Solar System.
Trujillo works with computer software and has examined the orbits of the numerous trans-Neptunian objects (TNOs), which is the outer area of the Solar System that he specialized in. Trujillo, along with Michael Brown and David Rabinowitz, discovered Eris in 2003. As a result of the discovery of the satellite Dysnomia, Eris was the first TNO known to be more massive than Pluto.