Provided is a constant current circuit supplying a temperature-compensated constant current. The constant current circuit includes a BGR circuit, a temperature dependent current generator, a reference current generator, and an output current generator. The BGR circuit generates a reference voltage with low voltage dependence. The temperature dependent current generator generates a temperature dependent current having a positive temperature coefficient. The reference current generator generates a temperature-compensated reference current by using the reference voltage and the temperature dependent current. The output current generator generates an output current based on the reference current generated by the reference current generator.