Therapeutic advancement for mesothelioma has been stagnant, with minimal treatment innovation in the past decade. Recently, however, immune checkpoint blockade (ICB) targeting the programmed death 1 and cytotoxic T-lymphocyte-associated antigen 4 pathways has revolutionized the treatment of multiple malignancies and shown promise in mesothelioma, with multiple agents now recommended in the salvage setting for advanced disease progressive on platinum-based chemotherapy. Studies of frontline chemoimmunotherapy and ICB combinations have also been encouraging, and both are likely to become integrated into the frontline treatment strategy for mesothelioma in the coming years. Other novel immunotherapy strategies, including chimeric antigen receptor T-cell therapy, are being investigated in mesothelioma. Although early studies have demonstrated the safety of multiple agents, further trials powered for efficacy are needed. In addition, enrolling patients in window-of-opportunity trials of ICB in resectable mesothelioma and biomarker-focused correlative studies will be critical to furthering the mechanistic understanding of ICB in mesothelioma, which in turn will help to uncover biomarkers of response and resistance in these patients.