With advancements in thin-film deposition, nanofabrication, and material characterization techniques, quantum devices leveraging nanoscale quantum phenomena have emerged across various fields, including quantum computing, sensing, communication, and metrology. Among these, quantum sensing harnesses the unique properties of quantum systems to achieve highly sensitive and precise measurements of physical quantities such as magnetic and electric fields, temperature, pressure, and even biological events. In this Perspective, we highlight some popular magnetic quantum sensors used for magnetic sensing and imaging, and emerging spintronic quantum sensors that exploit the quantum mechanical properties of electron spin for similar applications. Most of the techniques discussed remain in lab-based stages, with limited preliminary data reported. However, the authors believe that, with continued progress in spintronics, these nano- and micro-scale spintronic devices-offering superior and unique magnetic quantum properties-could open new horizons in biomedical applications, including single-cell and single-molecule detection, large-scale protein profiling, sub-micrometer resolution medical imaging, and beyond.