This study investigates factors affecting university student-to-student interaction within online learning platforms. A new model was proposed based on the United Theory of Acceptance and Use of Technology (UTAUT). The single-stage cluster-sampling method was employed, and 113 university students in Hong Kong were respondents. It was found that Information Quality, Social Influence, and Facilitating Conditions affect students’ intention to interact with each other. A quasi-full mediation model was established of the mechanism from Facilitating Conditions to students’ interaction behavior. The direct effect of Facilitating Conditions on students’ interaction and the effect of System Quality on the intention of student interaction were not significant. A fast network, computing facilities, and mobile-friendly software are possible candidates of the virtual environment conditions affecting the intention of student-interaction behavior within online learning platforms. Copyright © 2022 MDPI AG.