A simple and facile one-step method for the synthesis of an organic dye-functionalized polyoxometalate (POM) hybrid with visible-light photo-response was reported. The POM hybrid was fully characterized via single crystal XRD, powder XRD, FTIR and elemental analysis. The reaction of the organic dye with inorganic salts gave the dye-functionalized POM (MoBB3), in which the POM cluster was formed in situ. The electronic absorption peak of this hybrid was successfully extended beyond 680 nm. Photoelectrochemical measurement indicated that MoBB3 was photoresponsive under visible-light illumination, suggesting that it is an n-type (electron conductive) semiconducting material. This result might offer a method for the design of novel organic dye-functionalized POMs for photoelectric applications.