BackgroundMillions of children are diagnosed with a traumatic brain injury (TBI) each year, most being mild TBI (mTBI). The effect of mTBIs on academic performance is of significant importance. We investigate mTBI's impact on parent‐reported academic outcomes in school‐aged pediatric participants.MethodsThis cross‐sectional survey study queried parents (N = 285) regarding letter grade performance and the presence or absence of academic accommodations before and after an mTBI, including complicated mTBI (c‐mTBI, or mTBI with radiographic abnormality).ResultsWe found a parent‐reported decline in letter grades following c‐mTBI (p < .001), with no significant change following uncomplicated mTBIs. Degree and length of recovery were also associated with grade changes (p < .05). Those with no academic accommodations prior to the injury showed significant decreases in grades after injury regardless of post‐injury accommodation status (p < .05).Implications of School Health Policy, Practice, and EquityThis study underscores the need for an improved framework of support to maximize academic performance of children following mTBI, especially in those with a c‐mTBI and still recovering from their injury.ConclusionOur study identifies children who are at risk for adverse academic outcomes following mTBI. We encourage efforts to better support school nurses in this effort, including improved communication between health care teams and school teams.