Background: Many patients diagnosed with advanced non-small cell lung cancer (NSCLC) will develop intracranial metastasis, contributing significantly to morbidity and mortality. Immunotherapy (IMT) has emerged as the standard of care in select cases of metastatic NSCLC, though data investigating the survival impact of IMT and radiation (XRT) in these patients is limited. To characterize the survival impact of intracranial XRT and IMT in NSCLC patients with brain metastasis, we analyzed the National Cancer Database (NCDB). Methods: We queried the NCDB for patients with metastatic NSCLC having brain metastasis receiving intracranial XRT ± IMT. Univariable and multivariable analyses identified characteristics predictive of overall survival. Cox proportional hazard ratios with propensity matching mitigated indication bias between the two arms. Results: 13,998 NSCLC patients who received IMT (n = 545) or did not receive IMT (n = 13,545) were eligible for analysis. Univariable analysis demonstrated a median overall survival of 13.1 months (95% CI: 11.8-15.0) vs. 9.7 months (95% CI: 9.5-9.9) (p < 0.0001) and 3-year overall survival of 17% vs. 12% [p < 0.0001; HR: 0.77 (0.71-0.84)] in patients receiving and not receiving IMT respectively. Patients with N3 disease and those diagnosed between 2012 and 2014 were more likely to have received IMT. Receipt of IMT remained an independent predictor of increased survival on propensity score matched multivariable comparison (p = 0.0002). Conclusions: Receipt of IMT was an independent predictor of increased overall survival in patients with NSCLC having intracranial metastasis. Randomized, prospective studies are needed to further validate these findings.