Theo Sandfort (in full, Theodorus G.M. Sandfort) is a research scientist at the HIV center for clinical and behavioral Studies, and is associate professor of clinical sociomedical sciences in psychiatry, Columbia University. Before joining the center, he was Chairman of the Interfaculty Department of Lesbian and Gay Studies at Utrecht University, the Netherlands, and Director of the Research Program "Diversity, Lifestyles and Health" at the Netherlands Institute of social sexological research. Dr. Sandfort has engaged in numerous basic and applied empirical investigations in the field of sexuality and health.
Among MAPs, AAMs and their allies, Sandfort is known for his research on man/boy sexual relationships and early childhood sexuality.