Ultrasound at sufficiently low amplitudes, specifically in the MHz frequency range, does little harm to the biological samples (such as cells and tissues) and provides an advantageous and well-controlled means to efficiently power microswimmers. In this review, a state-of-the-art overview of ultrasonically propelled micro- and nanorobots from the perspective of chemistry, physics, and materials science is given. First, the well-established theory of ultrasound propulsion for micro/nanorobots is introduced. Second, the setup designs for ultrasound propulsion of micro/nanorobots are classified. Following this, the presentative fabrication methods of ultrasonic micro/nanorobots are summarized in detail. After this, the mechanisms of ultrasound propulsion for micro/nanorobots are explored and discussed. The hybrid motion of magnetic-, light-, and catalytic-driven micro/nanorobots with ultrasonic actuation is then summarized and discussed. Subsequently, this review highlights and discusses representative potential applications of ultrasound-powered functional micro/nanorobots in biomedical, environmental, and other relevant fields. Lastly, this review presents a future outlook on the ultrasound-driven micro/nanorobots.