Despite similarities between self-directed learners and successful postsecondary online learners, infrequently has self-directedness been examined in this population. Understanding the impact of self-directedness on online learner academic success and persistence may clarify the profile of a successful online student. Independent samples t-tests noted significantly lower PRO-SDLS total scores among learners that had withdrawn from an online course than among those who had not (t [184] = 2.66, p < 0.05) and significantly higher PRO-SDLS initiative scores among exclusively online learners than among residential online learners (t [187] = 2.32, p < 0.05). These findings, gathered from 189 online learners at a large, private university, may inform the development of effective online learner readiness assessments, targeted advisement strategies, and thoughtfully designed postsecondary online courses.