This dataset provides an insight into the reality and experiences of online learning as perceived by secondary school students in Vietnam during COVID-related school closures. The dataset addresses four main aspects of online learning, namely (a) students’ access to learning devices, (b) their digital skill readiness, (c) their experience with online learning and assessment activities, and (d) their overall evaluation of the effectiveness of online learning. The survey was administered online via Google Form from September to December 2021 with responses received from 5,327 secondary school students in 5 provinces of Vietnam. The dataset is expected to benefit local educators, administrators, and teachers who are interested in COVID educational practices and pedagogical interventions. The dataset can also benefit international researchers who wish to conduct comparative studies on student online learning or who wish to seek further insight into the responsiveness of an educational system to pandemic situations.