Immune checkpoint blockade (ICB), which harnesses the body's immune system to recognize and kill cancer cells, has transformed the management landscape for patients with advanced non-small cell lung cancer (NSCLC). Building on the success of this approach, clinical and translational researchers are attempting to augment the benefit of anti-programmed death 1/programmed death ligand 1 monotherapy through the addition of other therapies, such as conventional cancer treatments. This article reviews the potential use of immunotherapeutic strategies combined with radiation therapy in patients with NSCLC, focusing on ICB. It describes the mechanism of action of immune checkpoint inhibitors, summarizes published studies that demonstrate the benefit of immune checkpoint inhibitors in advanced NSCLC, and provides the preclinical and clinical rationale supporting the potential immunologic synergy of radiation and ICB.