Rapid progress in the theory, engineering, control and measurement now allows macroscopic mechanical systems to exhibit unambiguously quantum mechanical effects. Today, researchers are leveraging the quantum behavior of these novel devices to impact many disparate goals. These include, for example, precision sensing, metrology, quantum information processing, transduction, and fundamental physics. This meeting will bring together scientists from these areas to discuss the most recent experimental and theoretical advances in mechanical systems in the quantum regime. Just as the techniques of quantum optics revolutionized the control and measurement of light, the rise of quantum acoustics now promises novel approaches to measurement science and the study of quantum physics.