388 Charybdis (, prov. designation: or ) is a very large background asteroid, approximately in diameter, that is located in the outer region of the asteroid belt. It was discovered by French astronomer Auguste Charlois at the Nice Observatory on 7 March 1894. The carbonaceous C-type asteroid has a rotation period of 9.5 hours. It is probably named after Charybdis, a sea monster in Greek mythology.