Since 19th Century, Brunei Darussalam has conducted Islamic Lifelong Learning formally and non-formally which has been referred to as the Adult Religious Class. The class is offered to mature students who had never attended or finished their formal religious education. The modules taught are mostly focused on al-Quran literacy skills and basic Islamic studies. Although these classes have been practiced for a long time, the term Islamic Lifelong Learning is still an uncommon term in the sultanate. Hence, this study proposes to explore and discover the term “Islamic Lifelong Learning” in the context of Brunei Darussalam. The study is based on documents review and analysis from past researchers and official websites. Furthermore, the findings have suggested that various classes have been established in Lifelong Learning which can be known as “Islamic Lifelong Learning”. Thus, the paper concludes that Islamic Lifelong Learning is a part of an ongoing learning in Brunei Darussalam which has been implemented and conducted either in mosques, balais, universities or institutes with particular Islamic modules consists of ‘Aqīdah, Sharī‘ah and Akhlāq.