Flow cytometry is a highly effective technique used across various biomedical research fields, including hematology, immunology, and oncology. Its influence extends to plant science, where it has been a critical tool for nearly 40 years, significantly advancing the field. Recent improvements in flow cytometers, along with enhanced calibration and tuning techniques, have made it possible to detect viruses using this method. The rise of flow virometry, a novel use of flow cytometry, allows for the identification, analysis, and characterization of individual viral particles. This innovation holds the potential to uncover new viruses, possibly even discovering viruses akin to the Mimi virus. The chapter outlines the use of flow cytometry and flow virometry for detecting and analyzing plant viruses and viral particles, detailing the materials, methods, and procedural steps required for effective virus detection and characterization.