Success in our 21st century schools is linked with students' mastery of a wide range of academic and technological skills that rely heavily on executive function processes. This article describes a theoretical paradigm for understanding, assessing, and teaching that emphasizes the central importance of six executive function processes: goal setting, cognitive flexibility/shifting, organizing, prioritizing, accessing working memory, and self-monitoring (Meltzer, 2007, 2010, 2013a). For each of these core processes, there is an emphasis on the effects of executive function on learning as well as some of the challenges experienced by students with learning disabilities. There is also a focus on the interactions among executive function processes, self-awareness, effort, and persistence as well as the major principles of intervention and treatment. [This article is based on the William Cruickshank Memorial Lecture presented in Toronto, Canada at the 32nd Annual Meeting of the International Academy for Research in Learning Disabilities, June, 2008.]