Academic red-shirting via voluntary delayed school entry is a debatable practice for students but has been argued a potentially viable practice for children with a range of disabilities by providing students “the gift of time.” The current study (n = 21,409) indicated that children with ADHD (n = 1057) were more likely to be red-shirted as compared to children without ADHD (n = 20,352). We examined the academic trajectories of those children with ADHD who were red-shirted versus children with ADHD who were not red-shirted. Results revealed no meaningful association of red-shirting with academic achievement across time. We subsequently examined the relationship of red-shirting and academic achievement among children with ADHD who received medication (n = 426) versus children with ADHD who did not receive medication (n = 631). Among children with medicated ADHD, the negative association of red-shirting with achievement across time was stronger but medication received was also associated with more severe symptoms of inattention across time, which may account for this relationship. Academic red-shirting does not appear to be especially beneficial for students with ADHD (medicated or not) in terms of academic achievement across time.