BACKGROUND: Cutaneous squamous cell carcinoma (CSCC) is a prevalent disease for which improved risk stratification strategies are needed. OBJECTIVE: To develop a novel prognostic model (herein "riSCC") for CSCC and compare riSCC performance to Brigham and Women's Hospital (BWH) and American Joint Committee on Cancer Staging 8 METHODS: Retrospective 12-center, multinational cohort study of CSCCs from 1991 to 2023. Clinical and pathologic risk factors, treatments, and outcomes were collected. Fine-Gray model was employed for each outcome with inverse probability of treatment weighting. A final model was trained for prospective use and estimation of hazard ratios. RESULTS: 23,166 localized CSCC tumors were included. riSCC prognostic model performed superiorly to American Joint Committee on Cancer 8th edition and Brigham and Women's Hospital T staging for all outcomes. At five years, the C-index for riSCC ranged from 0.74 for LR to 0.87 for DSD. LIMITATIONS: Retrospective study design CONCLUSION: riSCC prognostic model offers fine-grained risk estimates and improved stratification for important CSCC outcomes compared to T staging systems.