A current sensing device and an organic light emitting display device including the same are disclosed. The current sensing device includes a sensing unit selectively connected to a pixel and a reference current source through a sensing line. The sensing unit includes a plurality of resistors connected to a first node and setting a divided voltage according to a pixel current input from the pixel and a reference current input from the reference current source, a first MOS transistor connected between the first node and a second node, a second MOS transistor diode-connected to the second node, and a comparator having an inverting input terminal connected to a third node, a non-inverting input terminal connected to a fourth node, comparing a reference voltage charged at the third node when the reference current is input and a pixel voltage charged at the fourth node when the pixel current is input, and outputting a comparison result.