Osteochondral allograft (OCA) transplantation has become a reliable treatment for cartilage defects of the knee, with advancements in recent decades allowing for greater use and effectiveness. This review analyzes the evolution of OCAs through in vitro, translational, and clinical research, highlighting advancements in patient selection, defect characteristics, graft matching, storage, and intraoperative preparation. Looking at long-term clinical outcomes, the success of OCAs is significantly influenced by factors such as age, BMI, defect size, and several other intraoperative and demographic variables. Recent innovations, including orthobiologic augmentation, have augmented graft viability and integration. A number of variations in technique have allowed osteochondral grafts to be used for a wider range of lesions. In addition, emerging alternatives to OCA, technologies such as synthetic scaffolds and decellularized and cryopreserved grafts, show great promise, although more data are needed.