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The effect of using Ba2+ to modify the structure and dielectric and piezoelectric properties of Pb(1−x)Bax(Mg1/3Nb2/3)m(Zn1/3Nb2/3)y(Ni1/3Nb2/3)nTizO3(x = 0–0.15) ceramics near the morphotropic phase boundary has been investigated. It is found that increasing the content of Ba2+ leads to a sequence of structural transformations from heterophase state (tetragonal and pseudocubic phases) to a cubic state via an intermediate pseudocubic phase. The evolution of the dielectric and piezoelectric properties (sequences of transformations: normal ferroelectric →relaxor ferroelectric → paraelectric) is shown. It is stated that ceramics with x = 0.025–0.050 possess the optimal combination of functional parameters for use in low‐frequency receivers and actuators. They are characterized by high values of small‐signal and large‐signal piezoelectric coefficients d33 of 621 pC/N and ~1500 m/V (at E = 5 kV/cm), respectively, and also by increased values of dielectric permittivity ε/ε0 and tunability coefficient (К = [(ε/ε0(E = 0) − ε/ε0(E≠0))/ε/ε0(E = 0)]·100%), equal to ~7000 and ~80%, respectively (at E = 20 kV/cm). It is shown that for the creation of high‐power piezoelectric transducers it is necessary to use ceramics with x = 0.125, which differs with high values of the mechanical quality factor Qm and ε/ε0 (1406 and 10 890, respectively).