A vehicle seat includes a coupling bracket coupling the side frame to the floor-side seat supporting member and fixed to the side frame by welding joining. An upper part of the coupling bracket and a lower part of the side frame are overlapped with each other in an overlapped region. An edge of a first member as one of the coupling bracket and the side frame in the overlapped region is welded, in a first welding joining portion, to a second member as the other of the coupling bracket and the side frame. A joining hole extending through the first member in a plate thickness direction thereof is provided at a position in the overlapped region other than the first welding joining portion, and an edge of the joining hole is welded, in a second welding joining portion, to the second member.