Extensive research has shown elevated mental health difficulties among parents of children with autism compared to other parents. Although several studies have explored factors related to mental health among parents of children with autism, the factors that influence and promote well-being remain poorly characterised. Parents of young, newly diagnosed autistic children may also be particularly vulnerable to stressors that impact mental health and well-being. We examined child-, parent-, and family/socioeconomic factors associated with concurrent mental health and well-being among 136 parents of young children with autism, aged 13–48 months. Parental mental health was predicted by both trait negative emotionality and reported child autism symptoms, while well-being was predicted by parent factors alone, including trait extraversion and mindfulness. Broader child characteristics and family/socioeconomic contextual factors made no significant contribution in regression models. While the mental health and well-being of parents with young autistic children are associated with one another, unique predictors seem to exist. That well-being was uniquely predicted by a modifiable parent characteristic – mindfulness – suggests the potential for early supports to bring direct benefits for parents, in the context of raising a young child with autism. Lay abstract Raising a child with autism has been linked to mental health difficulties. Poor parental mental health is likely influenced by various factors – including child-, parent-, and family/socioeconomic characteristics. However, little is known about what influences and promotes well-being (as opposed to mental health) among parents of young, newly diagnosed autistic children who may be particularly vulnerable. We examined child-, parent-, and family/socioeconomic factors associated with each of mental health and well-being in a sample of 136 parents of pre-school-aged children. Parental mental health was linked to both child- (i.e. autism symptom severity) and parent-related factors (i.e. personality traits reflecting a tendency to experience negative emotions). By contrast, in additional to mental health difficulties, which were linked to well-being, only other parent-related characteristics (and not child characteristics) were related to well-being. These included personality traits reflecting a tendency to be more extraverted/sociable, and also mindfulness. Other child-related and family/socioeconomic context factors (including household income, parental education level) were not linked to parental mental health or well-being in this sample. These results support the idea that poorer mental health and well-being are not simply the opposite of one another. That is, while these two factors were related, they were linked to different personal characteristics. Perhaps most importantly, the link between well-being and mindfulness – a personal characteristic that parents can improve – suggests mindfulness-based interventions may be helpful in directly supporting parental well-being in the context of raising a young child with autism.