This thesis investigates the interrelationship between sex and gender under international human rights law and how this influences individual subject formations. The research combines feminist, queer and psychoanalytical theories to scrutinise the sexed/gendered human rights discourse, starting from the theoretical assumptions underpinning the interpretations of sex, gender, and the related notions of gender identity, sex characteristics and sexual orientation. Specific interpretations of these categories outline the definition of victims and perpetrators of sex/gender-based abuses. Human rights law has so far accounted for the diversity of sexed/gendered subjectivities only to a limited extent, being based on four axioms: there are only two sexes and two genders (m/f); sex is a natural fact and gender is a social construct (sex ≠ gender); gender is the metonymic signifier for women (gender = women); gender power relations take the asymmetrical shape of male domination versus female oppression (m > f). Interpretations of domination and subordination in relation to femininities and masculinities determine the scope of human rights protections. Gender-based analysis on subordination has predominantly concentrated on women as the vulnerable group subject to men’s domination. However, such a focus excludes the consideration of differences within the same groups of men, women and any other gendered individuals, and thereby the multiple, nuanced gendered dynamics between gendered subjects. In contrast, this research maintains that dominative and subordinate postures interchangeably attach to femininities and masculinities, depending on the subjects’ roles, their positionalities and the situational meanings of their acts. The examination of two case-studies, on the UN human rights treaty bodies’ vocabulary on medically unnecessary interventions upon intersex children and on the European Court of Human Rights’ narrative on sadomasochism, shows the limits of an approach to gender which is based on rigid dichotomic pairs of masculinity/femininity, domination/subordination and perpetrator/victim. Such an approach can hardly reveal the assumptions of gendered interplays and their impact on subject formation.