Piezoelectricity is the intrinsic coupling between electric fields and strains in materials. While piezoelectric sensors, actuators, and RF filters are ubiquitous and important components of existing microsystems, their potential is still largely underutilized in many application spaces. In this talk, I will discuss the physics, engineering, and applications of two novel classes of piezoelectrically enabled microsystems developed by the MEMS-Enabled Quantum Photonics group at Sandia National Labs: (1) piezoelectrically modulated photonic, phononic, and optomechanical integrated circuits and 2) piezoelectric-semiconductor hybrids for all-acoustic radio frequency signal processing and acoustoelectrically enhanced optomechanics. I will discuss these systems in detail and show how they are being used to make significant advances in both classical and quantum information processing applications.