Background Obsessive compulsive disorder (OCD) is a disabling condition associated with significant personal and societal burdens. Despite the availability of efficacious treatments, in most cases, the disorder remains unrecognized and untreated. Lack of knowledge (i.e. poor mental health literacy, MHL) regarding OCD may be an impediment to seeking treatment. Therefore, the current study assessed public knowledge and beliefs about OCD and examined factors influencing MHL. Methods Five hundred seventy‐seven US adults participated in a telephone survey. After hearing a vignette describing someone with OCD, participants’ MHL for OCD was assessed across three domains as follows: recognition of OCD, knowledge and beliefs about available help, and concerns about being negatively evaluated for reporting symptoms. Results The majority of participants (90.9%) reported that the symptoms were a cause for concern and that the person in the vignette should seek professional help (89.5%). However, only one‐third of respondents correctly labeled the disorder as OCD. More respondents were optimistic about the likely success of psychotherapy than medication, but primary care physicians were the most frequently reported source of professional help. Finally, less education, lower income, and being in an older cohort were associated with poorer recognition of OCD. Conclusions When presented with brief vignettes describing a person with OCD, most community members can recognize the benefits of seeking professional help. However, recognition of the disorder and knowledge of treatment options can be improved.