This study explores how parenting couples use their relationship to support each other after their child’s autism diagnosis by assessing the role of dyadic coping and parenting sense of competence as predictors of their coparenting quality. Mothers and fathers raising a child on the spectrum (N = 70 couples) individually completed self-report questionnaires measuring stress appraisal, dyadic coping, parenting sense of competence, and coparenting. Parents were recruited 1–36 months after their child’s autism diagnosis and data were analyzed using the actor-partner interdependence model. Parents’ dyadic coping and sense of competence were related to their level of coparenting. Partner effects were found as mothers’ dyadic coping was positively linked to fathers’ coparenting and a higher sense of competence among fathers predicted mothers’ coparenting. Further research is needed to understand how these effects evolve throughout the child’s development stages. Lay abstract: We investigated how couples support each other after their child’s autism diagnosis and whether this affects the way they work together to raise their child. We recruited 70 couples raising a child on the autism spectrum. Both partners were asked to complete the same questionnaires measuring how they perceived the experience of having a child on the autism spectrum, how they used their relationship to support each other during stressful situations, how competent they felt completing their parenting tasks, and the coparenting relationship to explore how they worked together as a team when parenting their child. Parents participated in the study 1–36 months after their child’s autism diagnosis. We used statistical techniques that allowed us to see the impact mothers and fathers had on each other. Overall, parents who felt more competent and supported by their partner worked better as a team to raise their child on the spectrum. Fathers invested in the coparenting relationship more when mothers felt more supported by fathers. Mothers invested in the coparenting relationship more when fathers felt more competent parenting their child. Further research is needed to better understand how we can support couples as their child gets older.