Attenuation on a receive path side in a pass band of a second filter is improved in a case where a first filter, which passes a receive signal, is an acoustic wave filter. A multiplexer includes a common terminal, a first terminal, a second terminal, a first filter, and a second filter. The first filter is an acoustic wave filter disposed on a receive path connecting the common terminal and the first terminal and passes a receive signal. The second filter is disposed on a transmit path connecting the common terminal and the second terminal and passes a transmit signal. The multiplexer further includes an LC filter. The LC filter is disposed on the receive path connecting the common terminal and the first terminal.