Transparent piezoelectric materials are capable of coupling several physical effects such as optics, acoustics, electricity, and mechanical deformation together, which expands applications for mechanical-electro-optical multifunctional devices. However, piezoelectricity, transparency, and Curie temperature restrict each other, so it is difficult to achieve high piezoelectricity with both good transparency and a high Curie point. In this paper, Sm-doped 24Pb(In 1/2 Nb 1/2 )O 3 -42Pb(Mg 1/3 Nb 2/3 )O 3 -34PbTiO 3 (PIN-PMN-PT) transparent ceramic with a high piezoelectric coefficient of 905 pC/N, excellent electro-optical coefficient of 814 pm/V, and high Curie-point of 179 °C is fabricated. Sm doping effect on the phase structures, piezoelectricity, ferroelectricity, optical transparency, electro-optical properties, and thermal stability is systematically investigated. Compared with PMN-PT transparent ceramics, PIN-PMN-PT transparent ceramics exhibit better temperature stability. Electro-optical modulation and energy conversion are achieved using PIN-PMN-PT transparent piezoelectric ceramic, which indicates that it has great potential to develop mechanical−electrical−optical multifunctional coupling devices for optical communication, energy harvesting, photoacoustic imaging, and so on.