An absorbent article for animals that includes a longitudinal direction, a width direction, and a thickness direction that are mutually orthogonal to each other. The absorbent article includes: a first nonwoven fabric that forms a first surface in the thickness direction; a second nonwoven fabric that forms a second surface in the thickness direction that is on an opposite side of the first surface, and that is attached to an animal such that the longitudinal direction is disposed along a waist of the animal; in a plan view, between a first side edge and a second side edge of the absorbent article in the longitudinal direction, a first region, a center region, and a second region that divide the absorbent article into three equal portions in the longitudinal direction; and an engagement portion that extends in the width direction in the first surface of the first region.