<p>Ultra-Precision Engineering (UPE) is a comprehensive field that concerns the design manufacture and measurement of ultra-precision components and systems. With the progress of new solutions to UPE the demand of advanced mechatronic systems with high-performance on freedom stroke resolution accuracy and bandwidth has been continuously increasing. This Special Issue is a collection of 13 excellent research papers published in Actuators showcasing and discussing new advances in actuators and mechatronic systems for UPE as well as ultra-precision machines.</p>