Purpose: This study examined the relationship between sexual orientation acceptance from others and suicide attempts among lesbian, gay, bisexual, transgender, queer, and questioning (LGBTQ) youth. Methods: We analyzed data from a 2018 cross-sectional survey of LGBTQ youth between the ages of 13 and 24 years across the United States. Youth reported sexual orientation acceptance levels from parents, other relatives, school professionals, health care professionals, friends, and classmates to whom who they were ''out.'' Adjusted logistic regression analyses were used to examine the association between sexual orientation acceptance and a past-year suicide attempt. Results: All forms of peer and adult acceptance were associated with reduced reports of a past-year suicide attempt, with the strongest associations found for acceptance from parents (adjusted odds ratio [aOR] = 0.52) and straight/heterosexual friends (aOR = 0.54). Youth who reported high levels of acceptance from any adult had nearly 40% (aOR = 0.61) lower odds of a past-year suicide attempt compared with LGBTQ peers with little to no acceptance. Youth with high levels of acceptance from any peer also had significantly lower odds of reporting a past-year suicide attempt (aOR = 0.55). These relationships remained significant even after controlling for the impact of each form of acceptance, suggesting unique associations with suicide risk for both peer and adult acceptance. Conclusion: Interventions aimed at increasing sexual orientation acceptance from supportive adults and peers have strong potential to address the public health burden of LGBTQ youth suicide.