Background <p>This systematic review and meta-analysis assessed the role of radiotherapy (RTx) in patients with unresectable or metastatic intrahepatic cholangiocarcinoma (ICC).</p> Methods <p>A systematic search of the MEDLINE, EMBASE, and Cochrane databases was conducted to identify relevant studies published before November 2024. Meta-analyses were performed to assess the median overall survival (OS), 1- and 2-year OS rates, and local control (LC) rates in patients with unresectable or metastatic ICC treated with RTx. For studies reporting hazard ratios (HR), OS was compared between patients receiving chemotherapy (CTx) with RTx versus CTx alone and between dose-escalated and conventional-dose RTx. The toxicity outcomes of the included studies were systematically reviewed.</p> Results <p>Nine articles (<i>n</i> = 1,792) were included in the analysis. Pooled analysis revealed a median OS of 15.59 months, with 1-year and 2-year OS rates of 69% and 38%, respectively. The one- and 2-year LC rates were 79% and 55%, respectively. Four studies comparing CTx with RTx versus CTx alone revealed that the combination group had significantly improved OS (HR, 0.67). Additionally, dose-escalated RTx was associated with better OS than conventional-dose RTx (HR, 0.53). Grade ≥ 3 gastrointestinal toxicity occurred in 3.7% of patients, and grade 5 toxicity was rare (0.3%).</p> Conclusions <p>RTx, particularly with dose escalation or in combination with CTx, may provide survival benefits with acceptable toxicity, supporting further prospective evaluations of unresectable or metastatic ICC.</p>