An acoustic wave filter device includes first and second acoustic wave filters provided on a piezoelectric substrate, an insulating layer that is provided on the piezoelectric substrate and has a smaller dielectric constant than the piezoelectric substrate, a first wiring conductor electrically connected to an electrode of the first acoustic wave filter, a second wiring conductor electrically connected to an electrode of the second acoustic wave filter, the first wiring conductor and the second wiring conductor facing each other on the insulating layer in plan view, and a ground conductor located between the insulating layer and the piezoelectric substrate in a region A circumscribing the first wiring conductor and the second wiring conductor on the insulating layer in plan view.