Prior research suggests that sex typicality (especially femininity of females, but also masculinity of males) relates to perceptions of attractiveness, for both heterosexual and homosexual individuals. Using videos from childhood and adulthood, we investigated how different components of sex typicality contributed to this effect, whether the sex of the evaluator or of the target moderated the effect, and how the relationship of attractiveness with sex typicality varied across the lifespan. In Study 1, videos of 45 female and 50 male heterosexual and homosexual adult targets (ages 18-30 years) were judged by 56 female and 65 male heterosexual and homosexual raters (ages 18-30 years). Results suggested that both heterosexual men and lesbians viewed more feminine women as more attractive. Femininity of appearance was a primary contributor to this relationship. Masculinity was not related to men's attractiveness. Study 2 used similar methodology (44 male and 46 female heterosexual and homosexual targets and 22 male and 20 female heterosexual raters). Study 2 replicated results of Study 1. In addition, Study 2 included ratings of childhood videos of targets (ages 0-15). Results suggested that childhood femininity related to attractiveness of both young girls and young boys and that the relationship became stronger for girls as they got older. The impact of femininity on attractiveness may, therefore, depend on both targets' sex and their maturity.