The Surgeon General classifies sexual minorities (i.e., lesbians, gay men, bisexuals) as a high-risk population for suicide. This three-paper dissertation sought to contribute to an understanding of suicide risk among sexual minorities by investigating sexual orientation differences in both distal (i.e., stigmatization) and proximal (e.g., access to firearms) cofactors of suicide. Specifically, the studies investigated: (Study 1) the impact of neighborhood-level structural stigma on changes in psychological distress among sexual minorities following a statewide vote to ban same-sex marriage, (Study 2) sexual orientation differences in gun ownership and gun safety policy beliefs, and (Study 3) sexual orientation differences in lethal method used in suicide. Data were drawn from three unique datasets, including the California Quality of Life Survey (Study 1; N=7,421), the General Social Survey (Study 2; N=4,554), and the National Violent Death Reporting System (Study 3; N=59,075). Statistical analyses were conducted in R and SAS 9.4 with analytic methods across studies including univariate and bivariate analyses, quasi-experimental methods, multivariate logistic regression adjusted for confounding, and complex survey weighting incorporating propensity score methods. Results from Study 1 demonstrated that sexual minorities residing in neighborhoods where a majority of constituents voted in favor of a same-sex marriage ban had a statistically significant mean psychological distress reduction in the time period immediately after the vote (=-4.06, 95% CI: -7.38; -0.73), with post-hoc analyses demonstrating that increased social support might have partially influenced the direction of these unexpected findings. Study 2 findings demonstrated that gay/bisexual men were more likely to endorse a gun safety law (aOR=3.24, 95% CI: 1.79 - 5.88) and less likely to report guns in the household (aOR=0.34, 95% CI: 0.18 - 0.65) than heterosexual men. Among women reporting a household gun, lesbian/bisexual women were more likely to be the personal gun owner (aOR=3.97, 95% CI: 1.43 - 11.03) than heterosexual women. Results from Study 3 showed that sexual minorities who died by suicide had reduced odds of death by firearm (aOR=0.62, 95% CI: 0.51 - 0.75) and increased odds of death by hanging (aOR=1.36, 95% CI: 1.14 - 1.63) and drug/poison ingestion (aOR=1.30, 95% CI: 1.04 - 1.62) as compared to the reference group of suicides; however, these patterns varied by gender. Findings from this dissertation demonstrate that sexual orientation differentially impacts distal (i.e., psychological responses to structural stigma) and proximal (i.e., access to firearms, use of lethal method in suicide) risk factors for suicide. Results from the research reported here can inform public health and clinical interventions to reduce suicide risk among sexual minorities.