Heel spur is a chronic inflammatory condition causing pain and other typical symptoms. Therapeutic recommendations include the use of several drug or orthotic/physical therapies, performed alone or in combination. Surgery is usually reserved for refractory conditions. Radiotherapy has been shown to ensure good clinical outcomes in this clinical setting. A systematic review was performed to describe the feasibility and effectiveness of radiotherapy in the treatment of heel spur, evaluating its role in alleviating pain and consequently ensuring a better quality of life. A case report of 45-year-old patient treated for refractary right hindfoot pain was reported. A single fraction of 6 Gy RT was delivered with symptomatic complete response at 2 months observed. A systematic database search was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The systematic review included studies describing heel spur treatment and providing complete information about radiotherapy. Fifteen articles published between 1996 and 2020 were reviewed. Study characteristic analysis resulted in seven prospective randomized studies and eight retrospective studies. Radiotherapy of painful heel spur seems to be safe and effective, with high response rates even at low doses and with an overall favorable toxicity profile. Predictive parameters and modern tailored treatment should be investigated with further studies.