Academic incivility can create divisiveness and affect learners’ sustainability towards degree attainment. Therefore, there is a need to empirically assess learner views on what constitutes academic incivility in higher education. To fill this gap, we developed the Incivility Indicators Instrument (i3), a multifaceted scale that measures the extent to which students view cumulative behaviors and dynamics as instances of academic incivility. To examine the reliability and factor structure of the i3, we conducted a two-part study with two samples of adults in the United States who were enrolled in higher education programs. In study 1 (N = 342), we conducted an exploratory factor analysis (EFA) and found the initial three-factor structure. In study 2, we administered the instrument to a validating sample (N = 510) and examined the stability of the three-factor model and scores through confirmatory factor analysis (CFA). In this study, we describe the results of the study, provide implications, and discuss future directions.