Research demonstrates that many voters use gender stereotypes to evaluate candidates, but does that stereotyping affect women’s electoral success? In this paper, we try to make headway in answering that question by combining a novel empirical strategy with subnational election data from California. Our strategy relies on two existing findings: first, that individuals are more likely to rely on stereotypes when they have less information, and second, that the average voter in elections held concurrently with national elections has less information about local candidates than the average voter in off-cycle elections. We therefore estimate the electoral effect of increased gender stereotyping by examining the difference in women’s win rates in higher-information (off-cycle) and lower-information (on-cycle) elections—and how that difference varies by constituency and the office sought. Our results show evidence of stereotype-consistent behaviours during on-cycle (low-information) races. We conclude that the direction and magnitude of the effect of gender stereotyping on women’s representation varies across institutional contexts.