Children and youth with autism spectrum disorder (ASD) often experience poor health outcomes and restricted participation within sport settings compared to those without ASD. Through application of the Quality Participation (QP) framework, sport program features which foster quality experiences (i.e., promote building blocks) for children and youth with ASD can be identified for inclusion in program structures. The purpose of this study was to examine participation experiences of parents and coaches in an 8-week tennis program designed for children and youth with ASD. Guided by a constructivist paradigm and case study methodology, six weeks of session observations, including informal conversations with children and youth (n=5) during breaks, were conducted. Semi-structured interviews with a coach (n=1) and parents (n=5) were performed starting in the final week of the program. Data was analyzed using thematic analysis, with patterns in relation to program feedback as well as perceptions and priorities of the six QP building blocks across data collection methods being identified. Both the coach and parents prioritized the QP engagement building block followed by belongingness, however the coach perceived the program as providing challenge, while parents perceived enhanced support in mastery. Session structure flexibility, providing encouragement and constructive feedback, and promoting social interaction within a small group were identified, through session observations and interview data, as necessary for program implementation. The findings contribute to disability sport literature by identifying engagement and belongingness as areas coaches should focus on to foster quality experiences within sport for children and youth with ASD.