Hyperbaric Oxygen Therapy (HBOT) is a therapeutic modality involving the administration of 100% oxygen at pressures higher than ambient air pressure at sea level. The primary mechanism of HBOT is the hyperoxygenation of damaged tissues through increased partial pressure enhancing oxygen delivery to affected areas. Multiple other mechanisms are involved such as vasoconstriction, collagen production, gas volume reduction, polymorphonuclear function, and free radical production. The physiologic effects of HBOT underpin its diverse applications in medical practice including acute emergency treatment, supplementary therapy for chronic diseases, and antimicrobial interventions. Untreated pneumothorax remains the sole absolute contraindication due to its life-threatening nature; other contraindications are relative, necessitating risk-benefit analysis. Especially in pregnancy, patients with implantable devices, uncontrolled hypertension, or a history of epilepsy. HBOT shows promise in sports medicine for its benefits on delayed onset muscle soreness (DOMS), muscle and ligament injuries, fractures, and concussion, potentially expediting athletes’ return to competition. Adverse effects of HBOT are generally limited or reversible, including barotrauma, oxygen toxicity, and hemodynamic alterations. Two types of hyperbaric chambers are available, including hard-shell hyperbaric oxygen chambers (mono-place and multi-place) and soft-sided portable chambers operating at lower pressures delivering 30% oxygen for shorter durations. While not FDA-approved for therapeutic use, portable chambers are increasingly employed in athletic recovery protocols. Finally, future research is required to bridge the knowledge gaps in HBOT emphasizing its applications, sports medicine rehabilitation, and safety protocols. This chapter provides a scientific foundation for understanding HBOT’s principles, applications, and potential while highlighting avenues for further investigations.