<p>Polycrystalline samples of Nd_0.7Ba_0.3Mn_1-xTi_xO₃ (<i>x</i> = 0.40, 0.50) manganites have been synthesized using an auto-combustion method. The structural, magnetic and dielectric properties of these manganites were investigated in detail using X-ray diffraction, magnetic measurements and impedance measurements, respectively. Analysis of the HR-SEM micrographs reveals that the samples with <i>x</i> = 0.40 and 0.50 exhibit microflake and microrod, like microstructures,&#xa0;respectively. Rietveld refinement of X-ray diffraction patterns confirms the coexistence of two crystallographic phases of tetragonal structure with <i>P</i>4<i>mm</i> and <i>I</i>4<i>/mcm</i> space groups. The temperature-dependent magnetization measurement reveals that these samples exhibit a paramagnetic-to-ferromagnetic phase transition at the Curie temperature. The value of the Curie temperature reduces with increasing doping of Ti⁴⁺-ions. Field-dependent magnetization measurements show the coexistence of ferromagnetic and antiferromagnetic components for both systems. The frequency and temperature-dependent ac-susceptibility exhibits spin-glass behavior. Impedance spectroscopy measurements exhibit that the resistivity of the manganites increases and the dielectric loss decreases with increasing Ti⁴⁺-ions concentration. They display a very high dielectric constant of the order of 10⁵. The activation energy (<i>E</i>_<i>a</i>) of the Nd_0.7Ba_0.3Mn_1-xTi_xO₃ manganites was found to be 0.33–0.44&#xa0;eV. The Jonscher power law reveals that the movement of charge carriers occurs through translational hopping. The Nyquist plots were used to investigate the dielectric behavior, to study the grain, grain boundary and electrode effects in the samples.</p>