This study addresses the broader issue of designing inclusive and accessible online courses for post-secondary students. One approach that can be used to assist with such efforts is Universal Design for Learning (UDL), which is the guiding conceptual framework for this study. This conceptual framework emphasizes inclusivity and accessibility as essential building blocks of quality pedagogy. Given the instrumental role instructional designers play in promoting and shaping online instruction, this phenomenological qualitative study examined the attitudes and perceptions instructional designers had towards inclusive and accessible online education, their views on UDL, and the degree to which such perceptions shape professional development for online instructors. The results of this study add to the emerging body of research related to the application of UDL principles in post-secondary institutions and online learning environments. The findings highlight the ambiguity surrounding inclusive and accessible pedagogy, points to UDL as a promising construct for inclusive online education, and shows a strong connection between what participants understood about inclusive and accessible education and what they covered in faculty development initiatives. Study results have implications for practitioners who design or deliver online courses, as well as those involved in promoting inclusivity and accessibility at post-secondary institutions. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]