Background: The life courses of sexually and gender diverse individuals are shaped by a series of events that include acceptance of one’s own sexual orientation or gender identity, the coming out process and socialization in the LGBTQ+ (for Lesbian, Gay, Bisexual, Transgender, Queer/Questioning, and other sexual orientations and gender identities represented by the plus sign) environment. Generally experienced in a cis-heteronormative context, this process is marked by stigma and discrimination and the social harms they can cause, including a higher-than-average prevalence of alcohol use. Objectives: To profile the alcohol use of sexually and gender diverse (SGD) youth from a life course perspective and to explore individual perceptions regarding the personal, social and cultural factors (including stigmatization and its consequences) modulating their consumption. Methodology: This qualitative descriptive study is grounded in symbolic interactionism. Semi-structured interviews lasting approximately 90 min were conducted with LGBTQ+ youth aged 18 to 30 using alcohol at least once a week. A thematic analysis was performed. Results: A total of 31 individuals aged 18–29 (average age: 25) were interviewed. The average score regarding alcohol use was 14.25 (Standard Deviation -SD-: 4–31), which corresponds to a moderate risk and indicates the need for a brief intervention. Our study documents how the higher alcohol use among LGBTQ+ youth is shaped by individual, community and cultural factors at different points in the queer life course. Among the factors influencing drinking are the emotions experienced when questioning sexual orientation and/or gender identity as well as the feelings resulting from stigma and discrimination. Our findings also indicate the influence of socializing in the queer community and meeting peers and partners, as well as that of LGBTQ+ cultural practices. Discussion: Our study indicates the need for grassroots-level interventions that work to mitigate social pressures in queer socialization contexts. Accordingly, any intervention, whether preventive or therapeutic, must consider the interplay of personal, social, community and cultural factors. Interventions regarding alcohol use must build on the strengths of community and the sense of belonging.