Analyzing a large international data set generated by a BBC Internet survey, I examined sex differences and sexual orientation differences in six personality traits: extraversion, agreeableness, neuroticism, disagreeable assertiveness, masculine versus feminine occupational preferences (MF-Occ), and self-ascribed masculinity-femininity (Self-MF). Consistent with previous research, sex differences and sexual orientation differences were largest for MF-Occ and for Self-MF. In general, heterosexual-homosexual differences mirrored sex differences in personality, with gay men shifted in female-typical and lesbians in male-typical directions. Bisexual men scored intermediate between heterosexual and gay men on MF-Occ; however, they were slightly more feminine than gay men on Self-MF. Bisexual women scored intermediate between heterosexual women and lesbians on both MF-Occ and Self-MF. Sex differences and sexual orientation differences in MF-Occ, Self-MF, and other personality traits were consistent across five nations/world regions (the UK, USA, Canada, Australia/New Zealand, and Western Europe), thereby suggesting a biological component to these differences.