Blended learning is an effective approach to instruction that combines features of face-to-face learning and computer-mediated learning. This study investigated the relationship between student perceptions of three types of interaction and blended learning course satisfaction. The participants included K-12 teachers enrolled in a graduate-level course. Results indicate that students (a) perceived interaction as important to their learning experiences and (b) were moderately satisfied in their blended learning course. The predictive model of student satisfaction including three types of interaction was reliable. Of the three types of interaction, learner-content interaction was the strongest predictor of student satisfaction when the course design involved a low amount of collaborative activities. Additionally, student personality was found to be a vital factor for interaction and satisfaction in this type of course design. Students who reported having an extroverted personality noted more interaction and a higher level of student satisfaction than those who self-reported as introverted.