An in-vehicle storage unit includes a base member adapted to be fixed to a vehicle body and having an opening portion, a case which is openable and closable with respect to the opening portion, a pivot via which the case is rotatably supported by the base member, a gear disposed on a side wall of the case, the gear being an arc-shape having a center at the pivot, and a damper disposed on the base member. The damper is engaged with the gear to provide a damping force to the case when the case rotates from a closed position, at which the case is closed with respect to the opening portion, to an open position, at which the case is opened with respect to the opening portion. When the case is at the open position, the gear is disposed within an inner space of the base member.