This study investigates the effects of welfare reform in the United States in the 1990s on voting among low‐income women. Using the November Current Population Surveys with the added Voting and Registration Supplement for the years 1990 through 2004 and exploiting changes in welfare policy across states and over time, we estimate the causal effects of welfare reform on women's voting registration and voting participation during the period in which welfare reform unfolded. During this time period, voter turnout was decreasing in the United States. We find robust evidence that welfare reform led to smaller declines in voting (about 3 to 4 percentage points, which translates to about 10% relative to the baseline mean) for women who were exposed to welfare reform compared to several different comparison groups of similar women who were much less exposed. The robust findings suggest that welfare reform had prosocial effects on civic participation, as characterized by voting. The effects were largely confined to presidential elections, were stronger in Democratic than Republican states, were stronger in states with stronger work incentive policies, and appeared to operate through employment, education, and income. (JEL D72, H53, I38, J21)