With the growth of online learning, as well as the use of technology to supplement in-person learning, technology has enabled many opportunities for creating highly interactive and highly accessible learning environments. However, it is important to design learning environments to be accessible to diverse learners and learners with disabilities. Educational institutions must comply with legislation such as the Americans with Disabilities Act, as well as moral and ethical concerns related to inclusive institutional cultures. As a result, educational institutions should provide professional development and the resources necessary to help faculty members develop accessible course content. Furthermore, the theory of Universal Design for Learning provides a framework for ensuring access to learning opportunities as a part of the course design process. UDL helped to ensure all learners can benefit from accessible learning experiences. This research study explored the use of online professional development and its role in creating accessible online learning environments. A questionnaire was distributed to faculty members to determine if the participation in professional development resulted in positive beliefs towards accessibility. In addition, faculty skills for creating accessible content were evaluated. Courses taught by participating faculty members were evaluated for accessibility using Blackboard Ally, and faculty members were asked about their familiarity with UDL. The research study determined that there was not a significant difference between faculty members who took online professional development compared to those who did not take professional development in relation to attitudes towards accessibility, as well as faculty skills in creating accessible content. The research study identified a significant difference in accessibility of online content, using Blackboard Ally accessibility scores, between faculty members who participated in professional development in contrast to those who did not. The study identified a broad familiarity of UDL principles amongst the faculty members who participated in the study. [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.]