Acquaintance-initiated sexually aggressive behavior (SAB) is a widespread problem on college campuses, and intervention strategies thus far have not produced sustained reductions in SAB. Peer-related social norms and cognitive processes underlying sexual decision-making have separately been implicated in SAB. The present study integrates this work by examining the effect of perspective (self vs. typical college male referent) on college men’s judgments of the justifiability of unwanted sexual advances, determining the cognitive processes underlying men’s misperceptions, and evaluating rape-supportive attitudes (RSA) as a correlate of the implicated processes. College men attracted to women (n = 217) completed the Heterosocial Perception Survey-Revised, in which they judged the justifiability of a man’s increasingly intimate sexual advances as a woman responds increasingly negatively. Participants completed the Heterosocial Perception Survey-Revised from their own perspective and from the typical college male perspective. Participants also completed questionnaires assessing RSA and demographics. Undergraduate men, and particularly those endorsing more RSA, greatly overestimated how much the typical college male perceives increasingly nonconsensual behavior as justified. Three cognitive processes were strongly implicated in this misperception. When responding from the self-perspective, RSA correlated significantly with all cognitive processes. These findings illustrate the utility of integrating work on social norms and cognitive processing to document the global effect of perspective on average justifiability ratings and the perspective effect on cognitive processes underlying the ratings. Future work should evaluate personalized normative feedback and cognitive-training approaches to target misperceptions of peers’ sexual judgments, given the well-established relation between sexual misperception and SAB risk.