Background: Few studies have explored community participation for autistic adults, with or without intellectual disability. This study aims to investigate how autistic adults participate in the community, and the childhood and adulthood factors that predict community participation in adulthood. Method: Eighty-four autistic adults (mean age 34 years; 67% with co-occurring intellectual disability) initially recruited as children and adolescents, participated in the current study. Community participation frequency and variety were measured in adulthood. Childhood and adulthood predictors of community participation were investigated. Results: Participants engaged in the community an average of 18.2 times (range 0-49) over the previous 30-day period, in an average of 6.3 different activities (range 0-13). Childhood and adulthood factors (autism symptoms, intellectual disability, living arrangements) were associated with community participation. Conclusion: Areas for additional support and resources were identified.