We aimed to compare sleep problems in autistic and non-autistic adults with co-occurring depression and anxiety. The primary research question was whether autism status influences sleep quality, after accounting for the effects of depression and anxiety. We hypothesized that autistic adults would report higher levels of depression, anxiety, and sleep problems compared to non-autistic adults, after controlling for these covariates. We recruited 208 adults (109 non-autistic, 99 autistic) through a crowdsourcing platform, Prolific. Participants completed the Pittsburgh Sleep Quality Index, the Center for Epidemiologic Studies Depression Scale, and the Generalized Anxiety Disorder 7-item scale. Statistical analyses included Mann-Whitney U tests to compare group scores and a generalized linear model to assess the effect of autism status on sleep problems while controlling for depressive and anxiety symptoms. Autistic adults reported significantly higher levels of depressive and anxiety symptoms compared to non-autistic adults. However, after controlling for depression and anxiety, autism status alone did not have a statistically significant effect on overall sleep quality. The findings suggest that while autistic adults experience more severe sleep problems, these issues are closely related to higher levels of depression and anxiety rather than autism status itself. This study contributes to the understanding of sleep difficulties in autistic individuals, highlighting the importance of addressing co-occurring mental health conditions. Further research should explore the specific factors that exacerbate sleep problems in this population.