An ultrasonic object detection device includes: a first echo prolongation determination unit that sequentially determines whether a measured echo time of an ultrasonic sensor is prolonged from a reference echo time; a second echo prolongation determination unit that determines whether an addition echo time is prolonged from the reference echo time when the measured echo time is not prolonged from the reference echo time, and the ultrasonic sensor detects a reflected wave, the addition echo time being obtained by adding, to the measured echo time, a time from termination of an echo to termination of a first reflected wave; and a short distance object detection unit that determines that an object is disposed within a short distance so as to receive the reflected wave while the echo is not terminated when one of the measured echo time or addition echo time is prolonged from the reference echo time.