Although fairness in assessment practices (APs) in traditional classes has gained noticeable attention in recent years, it has remained unexplored in online education (OE). Thus, this study explores Iranian university English teachers' perceptions of fair APs in OE. For this purpose, 21 university English teachers from Lorestan University and Ayatollah Borujerdi University, Iran, were selected using a purposive sampling method. They were invited to express their conceptions of fair APs by completing a reflective written statement questionnaire. The collected data were subjected to a thematic coding analysis. The results yielded three overarching categories: distributive justice (i.e., equality should be considered, equity is of paramount importance, and assessment practices should be tied with students' needs), procedural justice (i.e., voices of students should be heard, both consistency and flexibility are required, and assessment procedures should be transparent), and interactional justice (i.e., interpersonal justice is crucial and informational justice should be considered). The study concludes by proposing a range of implications for different testing stakeholders.