Tumours and tumour-like lesions of the patella are exceedingly rare, accounting for less than 0.2% of all osseous lesions. The majority are benign, with giant cell tumour (GCTs), chondroblastoma, and aneurysmal bone cyst being the most common entities. Malignant lesions, though much less frequent, include osteosarcoma, chondrosarcoma, vascular tumours, lymphoma, and metastases. Clinical presentation is often nonspecific, with anterior knee pain and swelling being the predominant features, which can overlap with non-neoplastic conditions such as infection, gout, brown tumour, and synovial chondromatosis. The unique anatomy of the patella poses diagnostic challenges as classic radiological markers of aggressiveness may be absent. Radiography remains the first-line modality, but cross-sectional imaging with CT and MRI as well as nuclear medicine also plays a critical role in lesion characterisation, staging, and surgical planning. Awareness of the relative incidence, age distribution, and imaging hallmarks of different lesions is essential for timely diagnosis and management. This chapter provides a comprehensive overview of benign, malignant, and tumour-mimicking lesions of the patella, highlighting diagnostic pitfalls and outlining a systematic imaging-based approach to improve clinical outcomes.