Students' motivation has been identified as a critical factor for meaningful engagement and positive academic achievement in various educational settings. In particular, self-regulation strategies have been identified as important skills in online learning environments. However, applying self-regulation strategies, such as goal setting, strategic planning, and reflect performance takes significant effort. Without motivation, students will not enact these types of strategies. Autonomous self-regulation has been investigated in traditional classroom settings and there is ample empirical evidence of a significant relationship between autonomous self-regulation and engagement and academic achievement. However, such research was limited in online learning environments. The purpose of this study was to investigate the factors that affected students' autonomous or self-determined forms of regulation as defined in self-determination theory (SDT). The study examined the relations between students' self-regulated motivation and four other variables (students' interests in the course, students' perception of their instructor's interaction type, students' technology self-efficacy, and students' perception of the degree to which their online learning environment used constructivist-based pedagogy), and the interactions among these variables in college online courses. In addition, the study examined the relationship between students' autonomous forms of regulation and their engagement, learning achievement, interaction behaviors, and satisfaction in the online course. For students' interaction behaviors, the total number of authored and read messages, the total number of visits to the content page, the total number of visited topics in the content page, and total duration spent in the content page were examined. One hundred forty students in 19 online courses participated in this study. The results of hierarchical linear modeling analyses revealed: (a) Both environmental factors, instructors' autonomy-supportive interaction and learning environments using constructivist-based pedagogy predicted students' autonomous self-regulated motivation (b) Students' autonomous self-regulated motivation predicted students' self-reported engagement, achievement, and satisfaction (c) Two personal factors, interest in the course and technology self-efficacy did not predict students' autonomous self-regulation (d) Students' autonomous self-regulated motivation did not predict any interaction behaviors. The findings from this study are largely congruent with prior theory and research in the fields of academic motivation, self-determination, and online learning, which note that environmental factors, instructors' autonomy-supportive interaction and constructivist-based pedagogy significantly affect students' autonomous self-regulation in online learning environments.