Migration data, broken down by gender, allow us to gain a better handle on how gender affects the many dimensions of migration, and policymakers to begin to identify and address systematic gender inequalities related to migration. In this report, the author focuses on two particular aspects of gender and international migration data. In the first part, the paper provides an inventory of sex-specific migration data collections that are currently available. In the second part, the paper utilizes some of the collections in the data inventory to illustrate the global patterns and trends in sex-specific migration patterns where there are large imbalances in the migrant populations. The paper finds limitations in the gender-specific details in multiple collections of migration data, which occurred most commonly in migration flow data and migration summarised by the origin and destination countries of migrants. These shortcomings can be better addressed in the future by extending National Statistical Offices’ methods of migration data collections to capture the gender identity and sexual orientation of migrants and include summaries of these dimensions in their published migration data.