A ball detent fluid coupling for liquid and gas applications has a ball-retaining sleeve on the socket that is retractable by hand for joining and for separating the socket and plug and is characterized by a pressure-actuated check valve mounted on a valve guide within the flow path to preclude backflow into the supply side of the coupling. The valve also operates to shut off the flow when the mating parts of the coupling are disconnected or when flow through the coupling is shut off. A conventional valve can be mounted in the fluid flow passageway opposite the pressure-actuated check valve to urge the mating plug and socket to decouple when the sleeve releases the ball detents from engagement with the plug and to stop flow in the discharge line. The coupling will typically be used at pressures of from about 5 to 130 psig.