Background: Father involvement in parenting has received scarce attention in the disability field. This qualitative study explored the involvement, roles and responsibilities of fathers of individuals with Intellectual and Developmental Disabilities (aged 5-24 years). Methods: Thirteen fathers participated in online, semi-structured interviews. Fathers were asked to describe their involvement in caregiving, their roles and responsibilities, and the factors that had an impact on these domains. Results: Fathers were involved in the direct and indirect care of their child, and provided support for their partner and any siblings, alongside work commitments. A range of individual, interpersonal and contextual factors impacted their involvement and parenting role. Conclusions: Fathers play an important role in the lives of children with Intellectual and Developmental Disabilities. Ways in which services could improve the quantity and quality of paternal involvement in parenting are discussed.