Plantar fasciitis is a common, chronic pain syndrome characterized by heel pain due to degenerative changes and microtrauma in the plantar fascia at its insertion on the calcaneus. It affects a significant proportion of the population across various age groups, especially those aged 40–60 years and is prevalent among both sedentary and active individuals. The pathophysiology involves repetitive mechanical stress leading to microtears, inflammation, fibrosis, and sometimes calcaneal spur formation, culminating in significant functional impairment and reduced quality of life. Diagnosis is primarily clinical, supported by imaging modalities when necessary. Management encompasses conservative measures such as activity modification, physical therapy, orthotics, and pharmacotherapy. Minimally invasive approaches include corticosteroid injections, platelet-rich plasma, extracorporeal shockwave therapy, and low-level laser therapy. Radiotherapy, particularly low-dose radiotherapy, presents an effective non-invasive option for refractory cases, exerting anti-inflammatory and anti-fibrotic effects through modulation of cellular and molecular pathways. Clinical evidence from prospective and retrospective studies validates radiotherapy’s efficacy in pain relief, functional improvement, and long-term symptom control with minimal toxicity. This chapter synthesizes current understanding of plantar fasciitis pathogenesis, clinical features, and comprehensive treatment strategies, highlighting the evolving role of radiotherapy as a valuable adjunct in multidisciplinary care.