A capacitive micromachined ultrasonic transducer and a method of fabricating the same are provided. The capacitive micromachined ultrasonic transducer includes a device substrate including a first trench defining a plurality of first portions corresponding to an element and a second trench spaced apart from the first trench; a supporting unit provided on the device substrate, the supporting unit defining a plurality of cavities; a membrane provided on the supporting unit to cover the plurality of cavities; a top electrode electrically connected to a second portion in the second trench through a via hole penetrating through the membrane and the supporting unit; and a through silicon via (TSV) substrate provided on a bottom surface of the device substrate, the TSV substrate including a first via metal connected to the plurality of first portions corresponding to the element and a second via metal connected to the second portion.