This study extends the literature on the component skills involved in oral reading fluency. Dominance analysis was applied to assess the relative importance of seven reading-related component skills in the prediction of the oral reading fluency of 272 adult literacy learners. The best predictors of oral reading fluency when text difficulty was fixed at a single reading level was word reading efficiency. When text difficulty varied based on readers' comprehension levels, word reading efficiency was also the best predictor with vocabulary and auditory working memory emerging as important predictors as well. Our findings suggest the merit of investigations into whether adults with low literacy may need vocabulary and auditory working memory strategy interventions to improve their reading fluency.