A semiconductor device having an electrostatic discharge (ESD) protection circuit and a method of testing the same may provided. The semiconductor device may include one or more stacked chips, each stacked chip may include a test circuit configured to output a test control signal and a selection control signal in response to a test enable signal, an internal circuit configured to perform an operation and output a plurality of test signals in response to the test control signal, at least one multiplexer (MUX) configured to select and output one of the plurality of test signals based on the selection control signal, at least one test pad configured to receive the selected test signal, and at least one electrostatic discharge (ESD) protection circuit configured to discharge static electricity applied through the test pad externally.