A switch and a multiplexer including the same are provided, which are applicable to selectively transmit the high frequency signal from an input terminal to an output terminal therethrough. The switch includes a switch device and a variable resistor. The switch device is connected between the input terminal and the output terminal, and the switch device includes a control terminal and is configured to be switched between ON and OFF according to a switch controlling signal provided to the control terminal. The variable resistor is connected to the control terminal and configured to change to a first resistance while the switch device is ON, and to change to a second resistance while the switch device is OFF according to a resistor controlling signal. The first resistance is higher than the second resistance, and the resistor controlling signal is changed corresponding to the switch controlling signal.