Vehicle seat

A vehicle seat comprising:

• a seat back including a pad and a seat back frame supporting the pad, and
• a headrest provided on a top of the seat back, wherein:
• the seat back frame includes:
• a base frame;
• a movable frame supported in a movable manner in a frontward-rearward direction with respect to the base frame;
• and biasing member biasing the movable frame frontward and being adapted to permit a rearward movement of the movable frame when a load having a given value or more is input therein;
• the base frame has an upper frame section supporting the headrest, and a pair of side frame sections extending in an upward-downward direction in respective positions on laterally opposite sides of the upper frame section;
• the movable frame has a back-receiving section located between the pair of side frame sections, and a pair of side support sections provided on respective ones of laterally opposite sides of the back-receiving section to project forward with respect to both of the back-receiving section and the side frame sections;
• respective front ends of the pair of side support sections are disposed to stop a rear surface of the pad which receives a rearward load from a back of an occupant and are disposed and configured to move rearward with the rearward movement of the movable frame;
• and
• the pad has an inner surface spaced apart from the projecting front end of each of the side support sections toward an outer side in a widthwise direction of the vehicle seat, with a concave portion for reducing a thickness of the pad being formed in a region of the inner surface of the pad to improve flowability of the pad with the rearward movement of the front end of each of the side support sections.