Objectives: The current study examined the association between alcohol use frequency (ie, days a week one consumes alcohol), sexual and gender identity, and bystander confidence to intervene in interpersonal violence (ie, bystander self-efficacy). Participants: Participants were 750 undergraduate students aged 18-25 (260 heterosexual men, 260 heterosexual women, 59 SM men [54 cisgender, 5 transgender men], and 171 SM women [169 cisgender, 2 transgender women]). Methods: Participants completed an online survey about alcohol and sexual behaviors. Results: Results indicated that (1) alcohol use frequency was positively associated with greater bystander self-efficacy, (2) heterosexual men, compared to heterosexual women, reported lower bystander self-efficacy, and (3) the association between alcohol use frequency and bystander self-efficacy was significant and positive among heterosexual, but not SM, women. Conclusions: Prevention efforts may benefit from targeting individuals who drink more frequently and ensuring that they have the skills to effectively intervene.