The present study explored (a) whether differences between students with and without ADHD in reading comprehension are explained by their executive functions, and (b) the unique and shared contribution of the various executive functions to reading comprehension ability. To address these questions, ninety-six adolescents with and without ADHD completed open-ended question tests following the reading of two expository texts, and a series of tasks to assess five EF--planning, cognitive flexibility, updating, inhibition, and monitoring. Findings demonstrated significantly lower performance on reading comprehension tests and executive function tasks, including planning, cognitive flexibility, updating, and monitoring for the ADHD group relative to the control. Critically, these four executive functions, separately, were also found as significant mediators of the difference observed in the reading comprehension ability between groups. When analyzed jointly, only monitoring remained a significant mediator over and above all others. Contrary to expectations, inhibition skill did not differ between groups, nor was it found to be a significant mediator, separately or jointly with other executive functions. These findings support the importance of executive functions in general and monitoring skill in particular for reading comprehension ability. Moreover, they suggest implications for the development of effective reading comprehension training and strategies suited to students with ADHD.