Osteochondral (OC) defects involve concurrent damage to articular cartilage and subchondral bone and remain difficult to repair because the OC unit is mechanically continuous yet biologically compartmentalized. Beyond structural loss, OC lesions develop a hostile microenvironment dominated by inflammation, oxidative stress, and matrix degradation, which accelerates tissue degeneration and undermines regeneration. These features impose coupled spatial, temporal, and interfacial constraints on therapy: drug penetration is limited in avascular cartilage, clearance is rapid in vascularized bone, and healing requirements evolve from early immunomodulation to later anabolic and differentiation cues. Hydrogel-based systems provide a versatile material and drug delivery platform to address these challenges by combining ECM-like hydration, tunable mechanical properties, and programmable molecular transport. This chapter reviews hydrogel material classes and architectural strategies for compartment-aware OC delivery, examines how cross-linking chemistries and dynamic networks couple mechanical behavior with drug transport and release, and summarizes hydrogel-enabled delivery of therapeutic payloads ranging from small molecules and growth factors to nucleic acids and extracellular vesicles. Key translational barriers are discussed, emphasizing the need for system-level designs that integrate pharmacokinetics, mechanical loading, and tissue remodeling to enable reliable and durable OC repair.