A multiplexer includes a common terminal, a first acoustic wave filter having a first frequency band as a pass band, and having a first input/output terminal connected to the common terminal, a second acoustic wave filter having a second frequency band higher than the first frequency band as a pass band, and having a second input/output terminal connected to the common terminal, an inductance element, and a first capacitance element. The first acoustic wave filter has a parallel resonator of which one end is connected to the first input/output terminal and another end is connected to a ground electrode, and the first input/output terminal is connected to the common terminal via the inductance element, and the first capacitance element is connected between a signal path between the one end of the parallel resonator and the inductance element, and a ground electrode.