Families are a critical context for healthy sexuality development. This study characterized family sexuality communication for autistic adults (age 18–30) without intellectual disability (n = 117) versus a neurotypical comparison group (n = 319). Parent-reported number of sexuality topics covered did not significantly differ by gender or autism/comparison group. Parents of autistic adults who covered few or no topics (31%) reported higher religiosity, lower comfort and self-efficacy, and were less likely to say that the adult expressed attraction or desire for relationships. Parents of autistic adults were more likely than comparison parents to perceive their young person as being uninterested or not ready to learn about sexuality topics. These results suggest that families of autistic people require support to convey sexuality-related knowledge and values.