An acoustic wave device includes a piezoelectric substrate including a piezoelectric layer, and an IDT electrode on the piezoelectric layer and includes first and second electrode fingers interdigitated with each other and coupled to mutually different potentials. A portion of the piezoelectric layer including the IDT electrode includes an intersection region. When a direction in which the first and second electrode fingers extend is an electrode finger extending direction, a direction orthogonal to the electrode finger extending direction is an electrode finger orthogonal direction, and the IDT electrode is viewed in the electrode finger orthogonal direction, a region where the first and second electrode fingers adjacent to each other overlap each other is the intersection region, the piezoelectric layer includes first and second regions with polarization directions different from each other, and the first region and the second region are positioned at least in the intersection region.