Objective/Background: Children with attention-deficit/hyperactivity disorder (ADHD) experience more sleep problems than typically developing children. In addition, higher rates of depression are experienced by mothers of children with ADHD compared to mothers of children without ADHD. This study aimed to determine whether particular sleep problems in children with ADHD are associated with specific maternal mental health difficulties. Participants: Female caregivers of 379 children with ADHD (5–13 years) participated. The child’s ADHD diagnosis was reconfirmed during recruitment by caregivers completing the ADHD Rating Scale-IV. Method: Caregivers reported on their mental health using the Depression Anxiety Stress Scale and their child’s sleep using the Children’s Sleep Habits Questionnaire. Unadjusted and adjusted regression analyzes were undertaken. Results: In the adjusted analyzes, there were small significant associations between most aspects of child sleep (i.e. Bedtime Resistance, Night Waking, Parasomnias, Sleep Duration, Daytime Sleepiness and Total Sleep Problems) and maternal Anxiety and Stress, with the exception of Sleep-Onset Delay. Bedtime Resistance, Sleep Duration, Daytime Sleepiness and Total Sleep Problems also had small significant associations with maternal Depression. Sleep Anxiety had a small significant association with maternal Anxiety only. Conclusions: This study demonstrates important connections between many child sleep problems and particular aspects of maternal mental health, suggesting adaptations to behavioral sleep interventions for children and mental health interventions for parents to take a family approach may be beneficial. Future research should consider the longitudinal associations between child sleep and parent mental health in an effort to inform future intervention approaches.