Cross-national research on electoral authoritarianism has a limited understanding of the role of economic growth in bolstering ruling parties due to its focus on hegemonic or dominant-party regimes, which bases conclusions on ruling party success and eschews comparisons with other regimes. This paper demonstrates the importance of growth-induced election gains in electoral authoritarian regimes by comparing the impacts of growth on largest-party vote shares across all regimes. Examining legislative and executive elections for a sample of roughly 130 countries between 1945 and 2020, we show that growth consistently increases largest-party vote shares and that this relationship is stronger in less democratic regimes. The results highlight economic performance as an important channel through which parties in autocracies can legitimate their authority and consolidate control over future elections. We conclude by discussing several ways that growth supports increased electoral dominance by a ruling party.