We examined stigma towards vignette characters representing diverse autistic characteristics (social, non-speaking, or repetitive interests or restricted behaviors; RIRB) among 259 South Korean and 240 American participants (age range = 18 [approximately] 74). Within each domain, participants were randomized to read a vignette depicting low or high support needs. Koreans reported greater stigma towards autistic characteristics and less awareness of and support for the neurodiversity movement than Americans. Autistic characters' support needs and rater characteristics (autism knowledge, neurodiversity endorsement, and contact quantity) predicted stigma in at least one domain, and after accounting for these variables, participants' nationality was suggestively associated only with stigma towards social characteristics and RIRB. Findings highlight the need for culturally adapted-training that provides contact with diverse autistic people.