Online instructors adopt various roles and perform various competencies in the design and delivery of online courses. In this study, online instructor roles are categorized into eight types including Subject Matter Expert, Course Designer and Developer, Course Facilitator, Course Manager, Advisor/Mentor, Assessor/Evaluator, Technology Expert, and Lifelong Learner. Through survey-based research with 141 online instructors, this study examines competencies that online instructors perform based on various roles. When rating competencies, overall categorical means for all the roles were rated above 4.00, which showed that they used all these roles. The highest rated items and lowest rated items are discussed in addition to the connection between research and practice in online teaching. Online instructors who participate in training and who collaborate with instructional designers rated the frequency with which they perform the competencies to be higher. This study has implications for online instructors, instructional designers, and administrators who design and deliver online learning and offer professional development for online instructors.