Microelectrodes are small scale electrodes used for electroanalytical detection which have found applications in a wide variety of research areas including biology, kinetics, instrumental development, and surface modification. In this review, we provide a summary of the theory and experimental parameters used for bioelectrochemistry applications of microelectrodes. We then delve into a review of select bio-analytical applications of microelectrodes from 2013 to 2018 and provide a discussion on future research directions. (C) 2019 The Electrochemical Society.