Most education systems were severely impacted by the COVID-19 pandemic, and as a result, learning shifted from face-to-face to online in higher education institutions. This unprecedented shift in the learning environment caused substantial challenges for students. The situation was more severe in developing nations such as Bangladesh, which lacked available resources and knowledge of online education to support their students. Recent studies suggest that students resisted online learning in various developing nations. To support online learning in developing nations, this study develops the Acceptance of Online Learning (AOL) scale comprised of both institutional and student-related factors. To validate the AOL scale, the study collected data from 441 students across 30 higher education institutions in Bangladesh to determine the factors explaining students' acceptance of online learning using AOL measurements. The results showed that institutional factors, such as technological sufficiency, instructor efficiency, and technical assistance play significant roles in students' acceptance of online learning in developing nations. These findings will help education policymakers and administrators in developing nations to assess the needs of students with respect to online learning, and the AOL scale will assist in the evaluation of students' acceptance of online learning in these nations.