We conducted a systematic review of the literature to assess the potential prognostic utility of geriatric nutritional risk index (GNRI) for head and neck cancer (HNC). We selected studies and extracted data after searching the Cochrane Library, EMBASE, and PubMed databases. The associations between GNRI and survival outcomes were explored by calculating hazard ratios (HRs) and 95% confidence intervals (CIs) through a random‐effects meta‐analysis. We included 11 studies that involved 2887 patients with HNC. The combined HR demonstrated significant associations of low GNRI with unfavorable progression‐free survival (HR = 1.87, 95% CI = 1.32–2.65, p < 0.001) and overall survival (HR = 3.04, 95% CI = 2.30–4.03, p < 0.001). The association between the GNRI and overall survival persisted across various subgroups. The GNRI could serve as a valuable prognostic biomarker for patients with HNC. Low GNRI scores are significantly associated with unfavorable survival outcomes.