Partial discharge (PD) occurs when insulation containing voids is subjected to high voltage (HV). If left untreated, PD can degrade insulation until, eventually, catastrophic insulation failure occurs. The detection of PD current pulses, however, can allow incipient insulation faults to be identified, located, and repaired prior to plant failure. Traditionally, PD is detected by using galvanic contact methods or capacitive/inductive coupling sensors. This article discusses the use of software-defined radio (SDR) for PD detection and localization and presents proof of principle experimental results that suggest that SDR can provide a simple and reliable solution for PD-based monitoring of HV insulation integrity.