The majority of research on bisexuality does not take into account the importance of bisexual visual identities. Appearance has often been trivialised, despite it being an integral part of forming and expressing our identities. A small body of literature on lesbians and gay men’s visual identities has found that appearance norms can serve a number of positive functions, including identity formation and maintenance, ‘coming out’ (signalling sexuality to others), recognition, attracting a partner, resisting heteronormativity, forming communities, and safe-guarding such spaces from voyeuristic or homophobic others. However, very little is understood about bisexual people’s visual identities. The feminist research reported in this thesis provides a mixed methods exploration (using semi-structured face-to-face interviews and photomethodology with 20 self-identified bisexual women, a quantitative questionnaire completed by a total of 494 bisexual, lesbian and heterosexual women, and a qualitative survey completed by 176 predominantly heterosexual university students) of bisexual women’s visual identities. The findings highlight that binary constructions of sexuality remain dominant within psychology and the wider culture. These dichotomous understandings are problematic for bisexual people because they continually position heterosexuality and homosexuality as the only viable identity options. This has resulted in the dismissal and marginalisation of bisexual women and their identity. This research fills a gap in knowledge around bisexual women’s appearance practices and (lack of) visual identities. A key finding was that bisexual women experience their identity in ways which are distinct from either lesbians or heterosexual women. Bisexual and heterosexual participants were able to describe visual images associated with lesbian, gay, and heterosexual identities, but in stark contrast they were unable to recognise any equivalent bisexual appearance norms or a bisexual visual identity. This raises a number of issues around the implications of bisexual women’s lack of validation and visibility, and highlights the necessity for psychologists to recognise the existence of bisexuality in order to address the continued overlooking and marginalisation of bisexual women and their identities.