Nasopharyngeal carcinoma (NPC) is a unique head and neck cancer endemic in East and Southeast Asia, where it is invariably associated with Epstein–Barr virus (EBV). Most patients with NPC present with locoregionally advanced disease (LA-NPC), harboring a proclivity for locoregional recurrence or metastatic recurrences to the bones, liver, and lungs. Recently with a promising efficacy of immune checkpoint inhibitor (ICI, PD-1 inhibitor) in recurrent and/or metastatic (R/M) NPC patients, chemotherapy plus PD-1 inhibitor has become the standard of care for R/M NPC. Many existing studies have shown that chemotherapy combined with immunotherapy could effectively improve the tumor control rate of R/M NPC with tolerable side effects. However, the synergistic effect and toxicity of immunotherapy combined with radiotherapy (RT) is not fully understood. The immune effects of RT could transform “cold” tumors into “hot” tumors and produce distant effects, supporting the possibility of combining RT with immunotherapy. Many preclinical and clinical studies have shown that the combination of RT and immunotherapy exhibits promising antitumor activity without significantly increasing toxicity. Radioimmunotherapy is expected to become an ideal treatment strategy for locally advanced and R/M NPC. However, due to the particularity of immunotherapy, the beneficiaries are limited, and population screening should be carried out before the combination of RT and immunotherapy, which puts higher requirements on the sensitivity and specificity of biomarkers. At the same time, the current combined immunotherapy mainly focuses on the combination of PD-1/PD-L1 inhibitors with RT, while other emerging immunotherapy methods have not yet been combined with RT. In the future, we still need to further explore the optimal combination of RT and immunotherapy and investigate more efficient biomarkers to improve patient survival and quality of life.