Autism is associated with significantly higher rates of internalizing and externalizing disorders compared to neurotypical (NT) individuals. Emotion dysregulation (ED) is prevalent in autistic individuals and has been proposed to underlie both internalizing disorders and behavioral challenges in autism. This study sought to use a meta-analytic approach to examine the magnitude of ED severity in autistic samples compared to NT and other clinical (OC) samples. Following a review of the literature, a total of 35 studies were included in the analyses. In general, when comparing autistic to non-autistic individuals, findings suggest a medium magnitude of difference in ED severity between autistic and comparison groups overall. Subgroup analyses indicate that autistic individuals experience significantly higher ED severity when compared to NT peers. However, when compared to OC peers, the effect is small, suggesting the severity of ED may be more similar between OC and autistic groups. Moderators were also explored, including autistic traits, age, and sex composition. These findings provide integral information about the severity of ED in autistic populations compared to other non-autistic populations, assisting in further clarifying the presence of mental health challenges in autistic youth.