The advent of genetic engineering strategies has transformed the landscape of cancer immunotherapy, leading to the development and adoption of CAR-T cell therapy. However, the current autologous CAR-T cell platform is hindered by several factors including limited potency against solid tumors and limited scalability across multiple patients, placing a heavy cost burden on patients. The development of stem-cell-based technologies is poised to provide an alternative “off-the-shelf” platform to the current CAR-T model, which can help overcome these issues. In this review, we examine the current state of stem-cell-based therapies encompassing potential stem-cell sources, engineering approaches, clinical implementations, and prevailing challenges facing the field.