We introduce, analyze, and describe subnational data on cross-gender friendships for nearly 200 countries and territories, using data from 1.38 trillion ties between 1.8 billion Facebook users. Homophily by gender exists nearly everywhere, with individuals‘ strongest ties exhibiting less homophily than their peripheral connections. Across countries, cross-gender friendship rates align with existing measures of gender disparities. Within countries, cross-gender friending rates correlate with support for gender equality. In the US, cross-gender friendships are rarer in areas with a larger White share of the population, higher incomes, and more per-capita religious congregations.