A booster seat for a pet within a vehicle includes a main body having a lower wall and sidewalls extending therefrom and terminating at a distal edge. The main body is transitional between a deployed configuration and a stowed configuration, with the distal edge being moved toward the lower wall as the main body is transitioned from the deployed configuration toward the stowed configuration. First and second braces are selectively positionable relative to the main body in first and second positions. In the first position, each brace extends between the lower wall and the distal edge to provide support to the main body to maintain the main body in the deployed configuration. In the second position, each support being moved away from the distal edge. The booster seat additionally comprises a first attachment body coupled to the main body and connectable with a portion of the vehicle.