Background: Limited information about school outcomes among children (especially early childhood) with lifetime history of head injury, including traumatic brain injury (TBI), may inhibit efforts to support their academics and physical and mental health. Methods: Baseline data (2016-2018) from the Adolescent Brain Cognitive Development (ABCD) study were analyzed to describe associations between parent-proxy reported lifetime history of head injury or TBI before age 9 and school outcomes and behavioral challenges among 9- and 10-year-old children. Results: Having a lifetime history of head injury before age 9 was associated with increased odds of parent-perceived poor school performance (adjusted odds ratio [AOR] = 1.44, 95% confidence interval [CI] = 1.14-1.81), a drop in grades (AOR = 1.28, 95%CI = 1.06-1.54), recent receipt of detentions or suspensions (AOR = 1.29, 95%CI = 1.02-1.65), and receipt of special educational services (AOR = 1.23, 95%CI = 1.08-1.41). Of those with a lifetime history of head injury, males displayed poorer school outcomes and greater behavioral challenges than females. Similar associations were observed between lifetime history of TBI before age 9 and worse school outcomes, with males continuing to demonstrate stronger associations. Conclusions: These findings underscore the importance of screening for history of head injury and TBI and providing training for school professionals to help ensure students with a history of head or traumatic brain injury have appropriate supports in place.