Evidence suggests that although attention-deficit/hyperactivity disorder (ADHD) is associated with deficits in executive function, not all individuals with ADHD present with deficits on tasks of executive function (EF). However, no known studies to date have investigated whether age and personality traits are factors that influence how the relationship between ADHD symptoms and executive functions differ between individuals. The present study sought to examine the individual roles of personality traits and age as they related to the association between symptoms of ADHD and performance on executive functioning tasks. Data from 1,063 participants between the ages of 18 and 85 from the Nathan Kline Institute: Rockland Sample was analyzed using moderation analyses using hierarchical regressions. Results indicated that personality traits were associated with worse performance on executive function tasks, while ADHD symptoms were associated with personality traits and increasing age. More ADHD symptoms were associated with better performance on EF tasks. Finally, neither personality factors nor age moderated the association between ADHD symptoms and EF performance in adults.