IMPORTANCE Disproportionate levels of violence exist in lesbian, gay, bisexual, queer, asexual, and other sexual identity (LGBQA+) communities, often starting in adolescence and young adulthood, but little research exists on the range of sexual violence (SV) experiences. OBJECTIVE To assess risk of experiences of sexual violence among California LGBQA+ adults during adolescence and young adulthood. DESIGN, SETTING, AND PARTICIPANTS This survey study analyzed data from Cal-VEX 2020, a state-representative survey of California residents aged 18 years and older, to assess associations between LGBQA+ identification and types of SV experienced in adolescence (ages 13-17 years) and young adulthood (ages 18-24 years) using gender-stratified adjusted logistic regression. Forms of SV included verbal, cyber, and coercion or physically aggressive sexual harassment; homophobic or transphobic slurs; and forced sex. EXPOSURE Sexual identity. MAIN OUTCOMES AND MEASURESThe outcome of interest was experiences with any 5 forms of sexual violence (verbal sexual harassment, homophobic or transphobic slurs, cyber sexual harassment, sexual coercion or physically aggressive sexual harassment, and forced sex) during adolescence or young adulthood. RESULTS A total of 2102 contacted individuals (response rate, 26.2%) completed the Cal-VEX survey and were included in these analyses. Among these, the mean (SD) age was 46.6 (17.7) years, 1149 identified as female, 953 identified as male, and 214 respondents (9.6%) identified as LGBQA+. Compared with heterosexual individuals, LGBQA+ individuals had significantly higher odds of having experienced homophobic or transphobic slurs (women: AOR, 14.65; 95% CI, 5.14-41.77; men: AOR, 14.17; 95% CI, 6.96-28.86) and forced sex (women: AOR, 5.35; 95% CI, 2.74-10.43; men: AOR, 2.68; 95% CI, 1.01-7.10) in adolescence. LGBQA+ women also had higher odds of having experienced verbal and coercion or physically aggressive sexual harassment in adolescence (AOR, 2.33; 95% CI, 1.30-4.19). In young adulthood, LGBQA+ individuals also had higher odds of having experienced homophobic or transphobic slurs (women: AOR, 18.58; 95% CI, 7.12-48.49; men: AOR, 16.73; 95% CI, 8.26-33.92) in young adulthood. LGBQA+ men also had higher odds of having experienced homophobic or transphobic slurs (AOR, 16.73; 95% CI, 8.26-33.92); verbal (AOR, 3.29; 95% CI, 1.44-7.53), cyber (AOR, 6.32; 95% CI, 1.50-26.52), and coercion or physically aggressive (AOR, 5.54; 95% CI, 2.08-14) sexual harassment; and forced sex (AOR, 21.26; 95% CI, 5.63-80.35) in young adulthood. CONCLUSIONS AND RELEVANCE This survey study found that adult LGBQA+ individuals were at increased risk for having experienced SV across the continuum during adolescence and young adulthood, consistent with prior research. Multifold solutions are needed to support LGBQA+ youth, including altering social norms accepting SV and homophobia, creating safer schools and other institutional environments, and supporting healthy sexual and romantic partnerships.