Advances in immuno‐oncology have significantly improved cancer therapy outcomes. Unfortunately, potent responses to immunotherapy have only been achieved in subsets of patients. Nanomedicines and biomaterials have enormous potential for making immunotherapy work better in more patients, which has been suggested by a large number of preclinical studies. However, it remains unclear whether and how these materials will really benefit cancer patients treated by immunotherapy. Therefore, reviewing current clinical studies on nanomedicines and biomaterials in immuno‐oncology may provide valuable information for future translation research. In this work, the clinical landscape of cancer immunotherapy involving nanomedicines and biomaterials, mainly Abraxane, Doxil, messenger ribonucleic acid (mRNA) nanovaccines, and a biomaterial scaffold‐supported autologous vaccine, is reviewed. Clinical results demonstrate the high potential of nano/biomaterials in immunotherapy, achieved by rationalized utilization of their targeted delivery and reduced toxicities/side effects. Future clinical translation in this field will likely benefit from designing rational combinations of nanomedicines and biomaterials with the right immunotherapeutics applied in the right patients/tumors, and this should be achieved with the help of immune biomarker analysis. By rationally utilizing the unique features and advantages of nanomedicines and biomaterials, they will highly impact patient care in combination with immunotherapy.