PROCYON (Proximate Object Close flyby with Optical Navigation) is an asteroid flyby space probe that was launched together with Hayabusa 2 on 4 December 2014 13:22:04 (JST). It was developed by University of Tokyo and JAXA. It is a small (70kg, approx. 60 cm cube), low cost spacecraft.

Procyon (a CMi, a Canis Minoris, Alpha Canis Minoris; ; ) is the brightest star in the constellation Canis Minor. To the naked eye, it appears to be a single star, the eighth brightest in the night sky with a visual apparent magnitude of 0.34. It is classified as a binary star system, consisting of a white main-sequence star of spectral type F5 IV–V, named Procyon A, and a faint white dwarf companion of spectral type DQZ, named Procyon B.