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.