Biosensors that incorporate a biological recognition element with a transducer offer a rapid, simple approach for selective detection of analytes. However, conventional rigid biosensors have limited capabilities for continuous on-body monitoring applications. The emergence of flexible electronics has opened new possibilities for developing conformal biosensing platforms that can intimately interface with soft, curvilinear surfaces like skin for non-invasive health tracking. This review covers the fundamentals of biosensor technologies and recent progress in flexible biosensors aimed at pointof- care diagnostics and medical monitoring. Key developments in materials, electrochemical sensing interfaces, microfluidics integration and wireless connectivity are highlighted. Examples of flexible biosensors for metabolites, electrolytes, proteins and nucleic acids are presented along with capabilities and limitations. Current challenges include improving biocompatibility, correlation with standard assays, wireless range, manufacturability, and regulatory requirements. Further research on translating flexible biosensor devices from initial proof-of-concepts to validated medical products is warranted. Overall, flexible biosensors hold immense promise to enable continuous personalized health monitoring.