Theoretical models suggest a non‐linear relationship between government size and long‐run economic growth. However, testing this hypothesis empirically in cross‐country studies is complicated by the endogeneity of government spending and the accurate identification of inflexion points. This paper examines the non‐linear hypothesis by incorporating threshold analysis in a cross‐country growth regression. The methodology utilizes a sample‐splitting framework and follows an objective strategy for identifying and testing changes in the slope. The results provide evidence in support of the non‐linear hypothesis for a broad panel of countries.