Numerous studies show that bodily states shape affect and cognition. Here, we investigated whether incidental physiological arousal impacted perceived familiarity for novel images depicting real-world scenes. Participants provided familiarity ratings for a series of high- and low-arousal emotional images, once after a cycling session (to increase heart rate) and once after a relaxation session (to reduce heart rate). We observed a novel match-effect between internal (physiological) and external (stimulus) arousal sources, where participants rated highly arousing images as more familiar when bodily arousal was also high. Interestingly, the match-effect was greater in participants that scored low on self-report measures of interoception, suggesting that these individuals are less able to correctly perceive bodily changes, and thus are more likely to confuse their physiological arousal with an external source. Overall, our findings underscore the importance of interactions between the mind, body, and stimulus, especially when it comes to subjective judgments of familiarity.