A multiplexer includes filters connected to each other at a common terminal, a low-frequency filter with a first pass band, and a high-frequency filter with a second pass band that is higher than the first pass band. The low-frequency filter includes an initial-stage filter section including at least one first elastic wave resonator located on the common terminal side among at least two elastic wave resonators, and a subsequent-stage filter section that includes a second elastic wave resonator other than the at least one first elastic wave resonator. A reflection coefficient in the second pass band when the initial-stage filter section is viewed from the common terminal side as a single component is larger than a reflection coefficient in the second pass band when the subsequent-stage filter section is viewed from the common terminal side as a single component.