The majority of research on loneliness considers gender by comparing the loneliness reported by men and women. Drawing on current conceptualizations of gender and its effects, we propose alternative ways in which gender should be examined in relation to loneliness. To do so, we consider multiple gender-related factors and the role of the social environment, particularly societal ideologies about what gender is and how it should be expressed. We provide examples of how this expanded conceptualization can contribute to an improved understanding of loneliness by focusing on the impact of gender nonconformity, gendered life experiences, and couple relationships. We highlight the need for more research and evidence to fill existing gaps in understanding. We conclude that the field can move forward by considering the role of biological sex, gender identity, gender expression, gender roles, gender relational experiences, and sexual orientation, as well as the social norms against which these are experienced. To truly examine the role of gender in loneliness, we need to consider the normative context where some, but not others, are minoritized and marginalized, as well as move beyond binary notions of gender to include those with nonbinary, transgender, and intersex identities.