An electrostatic discharge (ESD) protection circuit includes a substrate, a semiconductor layer provided on the substrate to have a first conductivity type, a first well provided in a first region of the semiconductor layer to have a second conductivity type, an insulating pattern provided in the first well to cross the first well, and first and second doped regions provided in an upper portion of the first well to have the first conductivity type. The first and second doped regions may be laterally spaced apart from each other with the insulating pattern interposed therebetween.