Strontium barium niobate (Sr0.3Ba0.7Nb2O6, SBN) thin films of good quality were deposited on silicon substrates by radio frequency magnetron sputtering at room temperature and under different deposition pressures. The surface morphology and thicknesses of the SBN thin films were characterized by field emission scanning electron microscopy, and it was found that the thickness increased as the deposition pressure increased. The nanocrystalline structure of the SBN thin films was observed for 10 and 30 mTorr deposition pressures. Ferroelectric properties were determined by measuring leakage current density, capacitance, and polarization. For the SBN thin film deposited at 30 mTorr, the remnant polarization, saturation polarization, and coercive field values were 20.67 μC/cm2, 12.23 μC/cm2, and 1.73 MV/cm, respectively.