Single phase Ba2+ ions doped BiFeO3 nanoparticles have been successfully synthesized with varied concentration (0.0 ≤ x ≤ 0.2) using the auto combustion method. The structural properties of Bi1−xBaxFeO3 (x-0.0, 0.1 and 0.2) nanoparticles reveal the formation of highly crystalline rhombohedrally distorted perovskites without undergoing any structural phase transformation analyzed via Rietveld refinement. The Pauling’s equation confirmed that Ba2+ ions doped BiFeO3 ceramics have much more negative enthalpy of formation (ΔHf) than undoped BiFeO3. A reduction of particle size has been observed up to x = 0.1 and then after increases, whereas the band gap shows a reverse trend. Magnetic and ferroelectric transition temperatures are found to be slightly shifted towards the lower temperature up to x = 0.1 and then higher temperature side which could be attributed to the particle size effect. Ba2+ doped BiFeO3 ceramic with concentration x = 0.2 exhibit larger magnetization as compared to others at room temperature, but these magnetization curves were not saturated. Remnant polarization is found to decrease from 7.693 to 5.141 µC/cm2 along with the doping of Ba2+ ions. The on-site d-to-d crystal field excitations of Fe3+ ions associated with 6A1g–4T1g or 6A1g–4T2g electronic energy levels, Fe13d–Fe23d inter-site electron transfer and inter-atomic O 2p–Fe 3d electronic energy levels are observed by the means of absorption spectroscopy.