Acculturation is a multidimensional process that entails the retainment of one’s heritage culture and/or adoption of a new culture (e.g., practices, values, and identifications). Previous research has found that an individual’s ethnic or racial identification, often used as a measure of acculturation for immigrant populations, may be a protective factor against substance use. In contrast, specific aspects of U.S. culture are associated with a greater likelihood of increased substance use. Cannabis is the most used substance in the U.S. and Latinx young adults may be at risk for unhealthy use. The current study examined the influence of ethnic/racial and U.S. national identification on perceptions of the typical cannabis user and willingness to use cannabis in the future. Young adults aged 18-26 (n = 397; 77% female, 68% second generation immigrant) who self-identified as Mexican American and as having had used cannabis at least once in the past were recruited from an online research platform and a university undergraduate research pool. Independent-samples t-tests indicated that male participants reported greater U.S. national identification (p < .001), favorability towards a typical cannabis user (i.e., prototype favorability; p < .05), willingness to use cannabis in the future (p < .001), and lower prototype similarity (p < .001) compared to female participants. Regression analyses indicated that participants who reported stronger ethnic/racial identification had more favorable perceptions of a typical cannabis user (i.e., a prototype) compared to those with lower ethnic/racial identification. In addition, greater cannabis user prototype favorability was associated with greater willingness to use cannabis. Participants who reported using cannabis in the past week, typically used cannabis in combination with alcohol and other substances, those who spoke mostly Spanish at home, who identified as female, and participants from the online web panel were more likely to report greater willingness to use cannabis in the future. Participants who reported stronger U.S. national identification were less likely to report willingness to use cannabis in the future in comparison to their counterparts. No association was found with ethnic/racial identity. More research is needed to further determine the mechanisms by which identity is associated with perceptions of risk and use of cannabis use among Mexican American young adults with the aim of aiding in prevention and cessation of cannabis abuse among this community.