A faucet mounted water filtration system includes a base having an inlet, a water receiving chamber, and at least one outlet. The inlet is configured to be coupled to a faucet. A body is coupled to the base. The body includes a filter compartment configured to house a filter cartridge. A cover is rotatably coupled to the body. A cam is operatively coupled to the cover. A valve operatively engages a surface of the cam. The cam is rotatable to move the valve to open and close a passageway to the filter compartment. A biasing element biases the cover to a default position.