Lung cancer remains the leading cause of cancer-related mortality worldwide, with non-small cell lung cancer (NSCLC) constituting the majority of cases. Radiotherapy plays a pivotal role in the multidisciplinary management of advanced NSCLC, particularly for patients with driver gene-negative tumors. Significant technological advancements in radiotherapy, coupled with the development of novel therapies such as immune checkpoint inhibitors (ICIs), have transformed its role from a purely palliative modality to a key treatment capable of improving survival. This article systematically reviews the three primary applications of radiotherapy in driver gene-negative advanced NSCLC: palliative treatment, management of oligometastatic disease, and brain metastasis control. It also provides an in-depth discussion of the synergistic mechanisms, clinical efficacy, and safety profile of combining radiotherapy with immunotherapy.