An ultrasonic sensor assembly includes an ultrasonic sensor apparatus, a holding member and a spring arrangement. The spring arrangement includes two spring portions, which are connected together by a connecting portion. The spring portions are partially secured to a housing of the ultrasonic sensor apparatus and are resiliently deformed between the housing and a rear surface of a bumper. The spring portions and a flange portion of the holding member cooperate together to clamp the bumper therebetween.