An acoustic wave device includes first and second electrode fingers provided on a first principal surface of a piezoelectric body. In a case that a portion where the first electrode finger and the second electrode finger overlap with each other when they are viewed from a first direction connecting the first and second end surfaces is an intersecting portion, and a distance between the first end surface and the second end surface in the piezoelectric body is a width of the piezoelectric body, a different width portion having a width different from the width of the piezoelectric body at a central portion of the intersecting portion in a second direction is provided in a region where the first end surface and the second end surface oppose each other.