Disclosed is a vehicle seat with a side airbag, which includes an airbag module with an airbag cushion accommodated therein, a seat back frame with the airbag module mounted thereto, a seat back pad provided with a bolster protruding forward at each of opposite sides thereof and an accommodation space allowing the airbag module to be accommodated therein; a bolster wire inserted into the bolster to support a side load of an occupant; and a side airbag guide configured such that a first side thereof is locked to the seat back frame and a second side thereof is coupled to the bolster wire, to guide a deployment direction of the airbag cushion.