Open universities can improve learning outcomes and overall satisfaction among adult learners by addressing and enhancing online learning motivation. By applying latent profile analysis (N = 494) and adult learner interviews (n = 16), this mixed methods study aimed to better understand adult learners' motivation profiles in online learning distinguished by relatedness, mastery and performance goal, and intrinsic and utility value. Quantitative results showed four profiles characterized by unique configurations of motivation. Specifically, three profiles (Highly Motivated, Average Motivation, Below Average Motivation) demonstrated level effects and one that demonstrated shape effects (Highly Motivated, Low Performance) emerged. Furthermore, the study showed motivational discrepancies in terms of adult learners' age and gender. Qualitative findings provided insight into how profile indicators manifest in adult online learning including how the various motivation dimensions co-occur as learners participate in various online learning activities. Integrating quantitative profiles and qualitative themes contributes to our understanding of not only how adult learners differ in their motivation, but also what these profile indicators look like in situ and relate to online courses design and activities. Practical implications for instructors, such as differentiated approaches to support adult learners' unique motivation goals and needs, are discussed. Finally, suggestions for future research are outlined, underscoring longitudinal trends in profile membership in adult learning research work.