An electrostatic discharge protection device including the following components is provided. A first PNP BJT includes a P-type region, first and second N-type well regions, first P-type, first N-type, and second P-type doped regions, and an N-type region. An NPN BJT includes first P-type and third N-type well regions, a second N-type doped region, a third P-type doped region, and a third N-type doped region. A second PNP BJT includes the first P-type and third N-type well regions, the third P-type doped region, the third N-type doped region, and a fourth P-type doped region. The second P-type doped region, the first N-type doped region, the third N-type doped region, and the fourth P-type doped region are coupled to a high voltage side terminal. The first P-type doped region, the second N-type doped region, and the third P-type doped region are coupled to a low voltage side terminal.