Fair assessment in the classroom is a concern from student, teacher, principal and public perspectives. Standards and policies also underscore fairness as a key underpinning for assessments. Perceptions of fairness impact students' socio-emotional and learning outcomes, and build confidence, trust and legitimacy for the assessment outcomes. However, a direct inquiry into students' perceptions of what a fair assessment means has received scant attention. Without appreciating students' perceptions, we lack insights into how students' perceptions of fairness impact their responses to assessment outcomes for learning and grading purposes. Therefore, this study leveraged the Classroom Assessment Fairness Inventory to investigate first-year undergraduate students' perceptions of fairness about their secondary school experiences in Ontario, Canada. The results present initial validity evidence for the inventory to support a fairness theory and practice in classroom assessment contexts.