This study examined the relationship between core symptoms of autism spectrum disorder, parental romantic expectations, and parental provision of sexuality and relationship education in an online sample of 190 parents of youth 12–18 years of age with a parent-reported diagnosis of autism spectrum disorder. Regression analyses were conducted separately for youth with autism spectrum disorder + parent-reported average or above IQ and youth with autism spectrum disorder + parent-reported below average IQ. For youth with autism spectrum disorder + parent-reported average or above IQ, autism spectrum disorder severity predicted parental romantic expectations, but not parental provision of sexuality and relationship education. For youth with autism spectrum disorder + parent-reported below average IQ, parental romantic expectations mediated the relationship between autism spectrum disorder severity and parent provision of sexuality and relationship education. This supports the importance of carefully considering intellectual functioning in autism spectrum disorder sexuality research and suggests that acknowledging and addressing parent expectations may be important for parent-focused sexuality and relationship education interventions.