A vehicle seat belt device including: a buckle that is positioned so as to face a corner formed by a seat cushion and a seat back those constitute a rear center seat, and to which a tang of a seat belt is detachably attached; a webbing that connects the buckle to a lower floor; a loop portion formed on a side surface part of the buckle; and a first band that is inserted into the loop portion, is engaged with the buckle at one extending end, and is fixed to the seat back at the other end, is provided.