An increase in the lateral dimension of a vehicle seat equipped with a tip up lock cancel mechanism is prevented. In a vehicle seat equipped with a tip up mechanism for retaining the seat cushion at least in a tip up position and a tip up lock cancel mechanism for releasing the seat cushion from a retained condition effected by the tip up mechanism in response to a forward tilting movement of the seat back, the tip up lock cancel mechanism includes a cable encasing member having one end fixed to the seat cushion and another end fixed to a back side frame via a fixing part, and a cable slidably received in the cable encasing member and having one end connected to the tip up mechanism and another end connected to a seat base, the fixing part for fixing the cable encasing member to the back side frame being located on an inner side of the back side frame.