Substantial uncertainty exists about the prevalence of depressive disorders in individuals with autism spectrum disorder (ASD). This meta-analysis quantitatively summarized studies that assessed the lifetime and current prevalence of unipolar depressive disorders in children, adolescents, and adults with ASD. We also examined demographic, methodological, and study moderators. This meta-analysis adhered to PRISMA guidelines. A total of 7857 articles were identified through 5 databases (PubMed, Web of Science, PYSCInfo, CINAHL, ProQuest Dissertations and Theses), forward searches, and backward searches. Two reviewers independently screened articles and extracted data. Sixty-six articles met inclusion criteria. Results indicated that the pooled lifetime and current prevalence was 14.4% (95% CI 10.3–19.8) and 12.3% (95% CI 9.7–15.5), respectively. Rates of depressive disorders were highest among studies that used a standardized interview to assess depressive disorders (lifetime = 28.5%, 95% CI 20.1–38.8; current = 15.3%, 95% CI 11.0–20.9) and required participants to report on their own depressive symptoms (lifetime = 48.6%, 95% CI 33.3–64.2; current = 25.9%, 95% CI 17.0–37.3). Rates were also higher in studies that included participants with higher intelligence. Lifetime, but not current, prevalence was positively associated with age and the proportion of the sample that was White. In conclusion, we found that the rates of depressive disorders are high among individuals with ASD. Compared to typically developing individuals, individuals with ASD are 4-times more likely to experience depression in their lifetime. These results suggest that individuals with ASD should be regularly screened and offered treatment for depression.