Sexual minorities use social media platforms at higher rates than heterosexual individuals, often to find and connect with other sexual minorities and the broader online LGBTQ+ community. These online connections may help normalize feelings and experiences as a sexual minority in a heterosexual-normed society by increasing exposure to more meaningful reference groups and helping to mitigate the negative impact of heterosexist norms. There has been relatively little research investigating online social connectedness (OSC) among sexual minority adults, the relation between OSC and positive psychological outcomes, and the role of OSC in lessening the impact of heterosexist norms. The goal of the present thesis was to examine the relation between OSC and positive psychological outcomes, and whether such a relation is mediated by compulsory heterosexuality (CH; i.e., heterosexist norms) and internalized heterosexism (IH; i.e., internalizing and accepting heterosexist norms). A sample of 298 sexual minority adults in the U.S. completed an online survey that included measures of OSC, CH, IH, and positive psychological outcomes including resilience, well-being, self-acceptance, and self-esteem. The hypothesized model, with CH and IH as serial mediators of the relation between OSC and positive psychological outcomes, along with a series of alternative models, were tested using structural equation modeling. Support was found for the hypothesized model, such that greater OSC predicted lower CH, which then predicted lower IH, which in turn predicted greater positive psychological outcomes. While several alternative models had adequate fit, the hypothesized model was best supported statistically and by previous literature. These findings provide insights into the psychological benefits of social media connections for sexual minorities and the potential for OSC to lessen the impact of heterosexist norms. This study also adds to the existing literature regarding OSC and sexual minority adults, expanding the literature from primarily focusing on sexual minority youth. Future studies should be more socio-demographically diverse and longitudinal in nature in order to help better understand the directionality of the relationship between CH and IH. The present findings may also inform the development of interventions aimed at decreasing CH and IH, which future studies should investigate more fully.