Under what conditions did newly enfranchised women turn out to vote at levels approaching men? This question is important because if women’s turnout lagged behind men’s, politicians’ incentives to advocate for women’s interests could remain weak even after suffrage. I argue that women’s turnout approached parity with men’s in localities with strong incentives to vote and to mobilize among the general population. This is because women faced barriers to voting and were, therefore, more likely to vote and be mobilized under the most favorable circumstances. I then propose that electoral competition determines the strength of voting and mobilization incentives and, therefore, the gender turnout gap. Using sex-separated turnout data in Norway, I demonstrate that the gap narrows in high-turnout competitive districts in systems with single-member districts and in high-turnout within-district strongholds in proportional systems. I probe generalizability of my findings in New Zealand, Austria, and Sweden.