In an hydraulic pressure supply apparatus for a transmission, it is configured to have a first hydraulic control valve supplying signal pressure to a pressure regulation port of a regulator valve that regulates discharged pressure discharged from a hydraulic pump to line pressure; a second hydraulic control valve regulating the line pressure and supply it to a lockup clutch; a connecting section connecting a hydraulic passage connecting the first hydraulic control valve and the pressure regulation port with a hydraulic passage connected to an output port of the second hydraulic control valve; and a selecting mechanism installed at the connecting section to select higher pressure between output pressures of the first and second hydraulic control valves such that the selected one acts on the pressure regulation port.