In this work, we investigated rare earth driven structural, Dielectric, electro-strain-polarization and magnetic behaviors of Er3+/BiFeO3 nano particles (NPs) synthesized via solid state route. From the XRD (X-ray Diffraction) measurements the average domain size was 23.7 nm as a result of the Er substitutions on the A-site in BFO, which also led to other structural modifications. The morphological studies were carried out via using FeSEM. The dielectric and complex impedance studies were carried out in the frequency range 2 MHz to 10 Hz at various temperatures. Significant decreases in the dielectric constant (ε') have been noticed as frequency has increased, while increases in the ε' have been recorded as the temperature has increased. The substitution of Er3+ ions resulted in a considerable increase in saturation polarization (Ps) is 1.884 μC/cm2 and saturation magnetization (Ms) is 3.27 emu/gm, as estimated by the ferro-electric hysteresis (P-E) loop and M-H hysteresis loop, correspondingly.