Disclosed are a piezoelectric element which can obtain a large strain with a low drive voltage, a liquid-jet head and a liquid-jet apparatus. The piezoelectric element includes: a lower electrode; an upper electrode; and a piezoelectric film which is made of lead zirconate titanate (PZT), and which has perovskite crystals having priority orientations of the (100) plane, the piezoelectric film being interposed between the lower electrode and the upper electrode. In the piezoelectric element, an X-ray diffraction peak position derived from the (100) planes of the piezoelectric film is within a range of 2.theta.=21.79 to 21.88.