A bicycle carrier apparatus for a vehicle may include a slide carrier configured to slidably move in forward and backward directions on a bumper back beam to be drawn out or accommodated, an extended support installed on the slide carrier to be extended and spread in both side directions and formed to carry a bicycle thereon, and an expandable box seated on the extended support and carried on the slide carrier, to have an accommodation space formed therein, and to be expanded or contracted in a spreading direction of the extended support when the extended support is extended and spread.