Doping effects of CuO on the sintering behavior and electrical properties of 0.94(${\text{Bi}}_{0.5}$${\text{Na}}_{0.5})$TiO₃–0.06(${\text{BaTiO}}_3)$–$x$CuO (BNT–BT6–$x$Cu) lead-free piezoceramic obtained by the conventional solid-state reaction method were investigated. Regarding the undoped system, it is already known that it presents the best densification values when it is sintered at 1150${}^{\circ }$C, however, the doped system was sintered at 1150${}^{\circ }$C, 1100${}^{\circ }$C, 1050${}^{\circ }$C, 1025${}^{\circ }$C, and 975${}^{\circ }$C to determine the effect of Cu on the densification process. Therefore, it was obtained that the CuO-doped samples sintered at 1050${}^{\circ }$C presented the highest density values and therefore were the ones chosen to perform the characterization tests together with the undoped system. The samples were characterized using X-ray diffraction (XRD), Raman microspectroscopy, and scanning electron microscopy (SEM) analysis, whereas the ferroelectric and dielectric properties were evaluated by means of ferroelectric hysteresis loops and impedance spectroscopy studies. As a result, the addition of CuO allowed an improvement in sinterability and densification, with the subsequent grain growth, and the improvement of the piezoelectric coefficient ($d_{33})$.Doping effects of CuO on the sintering behavior and electrical properties of 0.94(${\text{Bi}}_{0.5}$${\text{Na}}_{0.5})$TiO₃–0.06(${\text{BaTiO}}_3)$–$x$CuO (BNT–BT6–$x$Cu) lead-free piezoceramic obtained by the conventional solid-state reaction method were investigated. Regarding the undoped system, it is already known that it presents the best densification values when it is sintered at 1150${}^{\circ }$C, however, the doped system was sintered at 1150${}^{\circ }$C, 1100${}^{\circ }$C, 1050${}^{\circ }$C, 1025${}^{\circ }$C, and 975${}^{\circ }$C to determine the effect of Cu on the densification process. Therefore, it was obtained that the CuO-doped samples sintered at 1050${}^{\circ }$C presented the highest density values and therefore were the ones chosen to perform the characterization tests together with the undoped system. The samples were characterized using X-ray diffraction (XRD), Raman microspectroscopy, and scanning electron microscopy (SEM) analysis, whereas the ferroelectric and dielectric properties were evaluated by means of ferroelectric hysteresis loops and impedance spectroscopy studies. As a result, the addition of CuO allowed an improvement in sinterability and densification, with the subsequent grain growth, and the improvement of the piezoelectric coefficient ($d_{33})$.