An absorbent article for animals includes: a support body part which is detachably worn around the waist including the back and belly of the animal; and an absorbent main body part which is disposed along the back, crotch and belly of the animal and is detachably engaged with and fixed to the support body part. When viewed in a planar view in an unfolded state, the absorbent main body part is provided with: an engagement part which is disposed on at least one of end parts which are located at both longitudinal ends; an absorbent body; a tail opening part; and elastic members which impart a longitudinal contractive force to the absorbent main body part. The elastic members are disposed on both widthwise outer sides of the absorbent body and have a longer longitudinal length than the longitudinal length of the absorbent body.