In an automobile front portion structure, a dilatant impact absorbing body that is formed from a material having dilatant characteristics is accommodated at an inner side of a crash box and is fixed to a front end surface of a front side member. A length dimension in a vehicle longitudinal direction of this dilatant impact absorbing body is set such that, when an axial compressive deformation amount of the crash box becomes greater than or equal to a set value that is smaller than a maximum value of the axial compressive deformation amount, the dilatant impact absorbing body receives compressive load between the front side member and a front bumper reinforcement.