A fuel vapor treatment apparatus includes a fuel tank, a canister, a passage forming member, a pressure-regulating valve, an acceleration detector, and a controller. The fuel tank is for a storage of fuel to be supplied to an internal combustion engine for a vehicle. The canister recovers fuel evaporated from the fuel tank. The passage forming member defines a passage through which the fuel tank and the canister communicate with each other. The pressure-regulating valve is provided in the passage forming member to connect or disconnect the fuel tank and the canister. The acceleration detector detects an acceleration value of the vehicle, and the controller controls the pressure-regulating valve based on the acceleration value detected by the acceleration detector.