Primary hyperparathyroidism (PHPT) is a common endocrine disorder characterized by hypercalcemia and elevated or abnormally normal parathyroid hormone (PTH) levels, due to excessive secretion of PTH by 1 or more parathyroid glands. In this report, we discuss the diagnostic and therapeutic challenges posed by ectopic parathyroid adenomas, a rare but atypical presentation of PHPT. We present the case of a 36-year-old female with PHPT due to an ectopic parathyroid adenoma located in the submandibular region. The patient presented with bone pain and was initially evaluated with routine imaging studies, which were negative. [18F] F-choline positron emission tomography (PET)/Computed tomography revealed the ectopic adenoma, leading to successful surgical management. Ectopic parathyroid adenomas are rare but can occur in various locations, and functional imaging modalities such as choline PET can aid in their detection. Surgical resection remains the definitive treatment for parathyroid adenomas, with intraoperative PTH monitoring guiding the extent of resection. Proper evaluation and management of PHPT is essential to avoid significant morbidity. Our case adds to the growing body of literature on the importance of considering ectopic locations of parathyroid adenomas in patients with PHPT.