The parathyroid glands are small yet essential endocrine organs that play a crucial role in maintaining extracellular calcium homeostasis by synthesizing and secreting parathyroid hormone (PTH). Embryologically derived from the third and fourth pharyngeal pouches, these glands exhibit significant variability in both number and location. A thorough understanding of parathyroid anatomy and embryology is essential for clinicians involved in the localization and management of parathyroid disorders. Beyond gross anatomical considerations, parathyroid embryology is influenced by intricate molecular signaling cascades and transcriptional regulators, including GCM2 and TBX1. Disruptions in these pathways can lead to clinically significant congenital anomalies, such as parathyroid aplasia, hypoplasia, or glandular malposition. Understanding these developmental processes enables clinicians to anticipate anatomical variations, thereby improving both preoperative planning and intraoperative decision-making. This chapter provides a detailed review of the macroscopic anatomy, histologic architecture, and embryologic development of the human parathyroid glands, with a particular emphasis on clinically relevant anatomical variants and their implications for nuclear medicine imaging, radiologic localization, and minimally invasive surgical techniques. Special attention is given to recent data from surgical series, cadaveric studies, and imaging-based anatomical research, which continue to enhance our understanding of both normal and pathologic parathyroid anatomy.