An acoustic wave filter includes: a piezoelectric substrate; a first multimode filter that includes at least three first IDTs located on the piezoelectric substrate, has a first passband, and is connected between an input terminal and an output terminal; and a second multimode filter that includes at least three second IDTs located on the piezoelectric substrate, has a second passband, and is connected in series with the first multimode filter between the input terminal and the output terminal, a part of the second passband overlapping with the first passband, a remaining part of the second passband not overlapping with the first passband.