CT Chamaeleontis (CT Cha) is a T Tauri star in the constellation of Chamaeleon. It has an apparent visual magnitude which varies between 12.31 and 12.43.
In 2006 and 2007, a faint companion was observed 2.7 arcseconds away from CT Chamaeleontis, using the Very Large Telescope at the European Southern Observatory. Since the object shares common proper motion with CT Chamaleontis, it is believed to be physically close to the star, with a projected separation of approximately 440 astronomical units. It is estimated to have a mass of approximately 17 Jupiter masses and is probably a brown dwarf. The companion has been designated CT Chamaeleontis b.