Repetitive movements (RMs), colloquially called “stimming” among adult autistic people and “motor stereotypies” among scientists, are common in autism. These behaviors fall under the domain of restricted and repetitive behaviors in the current edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). RMs can be socially disruptive or cause self-harm, but can also be experienced as cognitively or emotionally helpful and even enjoyable. Overt RMs are less common in females than in males, which could contribute to clinical difficulties in detecting their autism. In the social domain, autistic people with intact intelligence can often mask their social difficulties through various compensation strategies, and females appear especially skilled at it. Subjective report from verbally able adults may be useful as a first step in detecting potential camouflaging of RMs, and to provide a foundation for further studies. We founded an Internet-based outreach platform that became particularly successful in reaching female and transgender individuals. We recruited 342 individuals to an anonymous online questionnaire, collected data about self-reported RMs and probed for potential camouflaging. The cohort comprised 56% formally diagnosed participants and 44% who self-identified as autistic, and 17% of all participants reported non-cisgender identity. Thus, in addition to diagnosed women, we reached two populations that would normally be excluded from autism studies: transgender and undiagnosed participants. We found high rates of RMs in both diagnosed and self-identifying participants, and a striking prevalence of camouflaging. We suggest that camouflaging of RMs may contribute to underdiagnosis of autism, at least in females and transgender people, and that further studies on this topic are exceptionally important.