In the last decade, immunotherapy (IT) has revolutionized oncology and found indications in many cancers, including hepatocellular carcinoma (HCC). In HCC, IT has become the leading systemic therapy for advanced diseases. At the same time, it carries the promise of being a valuable therapy in other settings, including intermediate-stage and unresectable disease, as a downstaging or conversion modality. More controversial is the role of IT in relationship to liver transplantation (LT): on one side, it could be a helpful tool to control or downstage HCC before LT or to treat tumor recurrence after LT, while on the other, it carries the risk of graft rejection and graft loss. This review aims to cover these concerns in depth and unravel the current literature.