Parents of children with ADHD experience levels of distress that negatively impact child, parent, and family functioning. However, current treatment approaches for ADHD focus on child interventions and disregard the effect of parental distress. Falk et al. (2014) developed Model A, further validated by Bones (2017), to demonstrate that the relationship between parental distress and child-centric variables (child social/interpersonal deficits and externalising behaviour) is mediated by parent-centric variables (socio-economic support and maladaptive parental cognitions) in ASD populations. The current study aimed to validate Model A in an ADHD population. This study recruited 142 parents of children aged 4 to 17 years old, with and without ADHD. Participants completed an online survey including measures of socio-economic support, maladaptive parental cognitions, child social/interpersonal deficits, and child externalising behaviour. Hierarchical regression was conducted and results indicated that parents of children with ADHD had significantly higher levels of distress compared to parents of typically developing children and that the variables in Model A were significant predictors of parental distress. Results suggest that parent-centric factors, particularly maladaptive parental cognitions, are important predictors of distress in ADHD parents. This study illustrates a need to focus on interventions that target parental distress when treating children with ADHD.