Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by levels of inattention or hyperactivity and impulsivity that are developmentally inappropriate. ADHD affects approximately 3–12% of children, with more boys being diagnosed than girls. The Diagnostic and Statistical Manual of Mental Disorders classifies ADHD as (1) combined inattention and hyperactivity/impulsivity; (2) predominantly inattention; and (3) predominantly hyperactivity/impulsivity. Conversely, the International Classification of Diseases requires the presence of inattention, hyperactivity, and impulsivity for a diagnosis of hyperkinetic disorder, the European label for ADHD. ADHD is a complex disorder that requires a rigorous diagnostic process that typically begins with a detailed family, developmental, medical, psychiatric, academic, and behavioral history. The next step involves a variety of assessments in areas including but not limited to neurological, intellectual, academic achievement, memory, attention, concentration, executive functioning, response inhibition, and behavior. One of the challenges in diagnosing ADHD is ruling out the nature of any comorbid conditions and ascertaining the primary condition should more than one secondary condition be identified. A variety of treatment and intervention approaches exist for children and youth with ADHD. The most common and most evidence-based approaches include the use of cognitive behavioral interventions, psychostimulant medication, or a combination of the two. In addition, a variety of instructional strategies have been found to be effective, particularly when combined with self-regulatory strategies, executive control, and active learner participation with a teacher or adult mediator. There is continuing debate as to whether learners with ADHD are better served in general classrooms or in more specialized settings. However, the solution is not to use one approach instead of the other. An effective program should meet the needs of learners using the appropriate combination of specialized supports and general classroom practices. Implementing such programs can place a lot of demand on individual teachers. The Universal Design for Learning (UDL) approach is designed to support teachers in responding to diverse learning needs and to focus on the limitations of the classroom environment rather than on the limitations of the learner has been developed and is demonstrating promise. UDL incorporates differentiated instruction to focus on curricular design techniques that emphasize setting motivational factors pertinent to learning, finding alternative and interesting ways to represent the material to be learned, and enabling alternative ways for learners to express their knowledge. Combined with creating safe and supportive classrooms for all learners, UDL affords a more planful approach, so responding to learning differences is not seen as an add-on but as an integral component of the teaching/learning process that combines various tiers of instruction aimed at meeting a wider range of learner strengths and needs.