A fastening apparatus for a vehicle may include: a first fastening unit fixed to a first structure; a casing fixed to a second structure and arranged in a manner that faces the first fastening unit; a guide unit formed in the casing in a manner that passes therethrough; and a second fastening unit installed on the guide unit in a manner that is rotatable and enabled to ascend and descend, and fastened to or separated from the first fastening unit according to a rotational direction thereof.