A circuit which is constituted by a plurality of n-channel transistors includes, in at least one embodiment, a transistor (T1) which has a drain terminal to which an input signal is supplied and a source terminal from which a output signal is supplied; and a transistor (T2) which has a drain terminal to which a control signal is supplied and a source terminal connected to a gate terminal of the transistor (T1). A gate terminal of the transistor (T2) is connected to the source terminal of the transistor (T2). With the arrangement, it is possible to provide (i) a semiconductor device which is constituted by transistors having an identical conductivity type and which is capable of reducing an influence of noise, and (ii) a display device including the semiconductor device.