Background: Unusual sexual interests are largely intercorrelated, yet not much is known about underlying patterns of clusters between various sexual interests. Aim: To identify underlying clusters of unusual sexual interests using exploratory factor analysis. Methods: We conducted exploratory factor analysis with self-reported interest in a wide variety of unusual sexual acts for an online, international sample (N = 669; 61% female), and for women and men separately. Factor regression weights were correlated to self-reported sex life satisfaction, sexual outlet, and psychiatric symptoms. Outcomes: Participants rated the attractiveness of 50 unusual sexual activities, and reported on their sex life satisfaction (Arizona Sexual Experiences Scale), sexual outlet, and symptoms regarding ADHD (Adult ADHD Self-Report Screening Scale for DSM-5), depression, anxiety, and stress (Depression, Anxiety, and Stress Scale). Results: We identified 5 factors of unusual sexual interests that were largely comparable for women and men: submission/masochism, forbidden sexual activities, dominance/sadism, mysophilia (attraction to dirtiness or soiled things), and fetishism. For women, unusual sexual interests related to more psychiatric symptoms and higher sexual outlet, whereas this relation was less explicit for men. Clinical Implications: Different factors of unusual sexual interests may serve different underlying functions or motivations, for instance related to sexual, and emotional regulation. A better understanding of the nature of unusual sexual interests is important to be able to influence sexual interests that are unwanted or cause damage to others. Strengths & Limitations: Strength of this study include its anonymity, the avoidance of sexual orientation effects, and the possibility to indicate only a slight endorsement toward sexual items. Limitations include the sample's generalizability and the truthfulness of online responding. Conclusion: Unusual sexual interests could be clustered into 5 factors that were largely comparable for women and men: submission/masochism, forbidden sexual activities, dominance/sadism, mysophilia, and fetishism. Schippers EE, Smid WJ, Huckelba AL, et al. Exploratory Factor Analysis of Unusual Sexual Interests. J Sex Med 2021;18:1615–1631.