Higher emotional clarity, the extent to which people unambiguously identify, label, and describe their own emotions, is related to a host of positive intrapersonal factors but its relation to interpersonal factors is unexplored. We hypothesized that emotional clarity would be related to cognitive empathy (i.e., perceiving others’ emotions) and to accurately understanding others’ negative affect (NA), but not positive affect (PA), in the context of a stressful situation. After completing self-reports of trait emotional clarity and cognitive and affective empathy (i.e., one’s emotional reaction to others), participants (N = 94 undergraduate students; i.e., perceivers) viewed a series of video clips of adults (i.e., targets) completing a stressful laboratory task in a previous research study. Before and after the stress task, targets reported their state NA and PA. While viewing the recordings, perceivers rated how they thought the targets were feeling at the corresponding time points. Correspondence between perceivers’ and targets’ affect ratings were used as indices of the outcome variable, performance-based cognitive empathy. As expected, self-reported emotional clarity was related to the self-reported cognitive, but not affective, empathy. Moreover, perceivers’ emotional clarity was related to higher cognitive empathy for NA not PA after the stressful task. Our findings provide preliminary support for the importance of emotional clarity in the ability to accurately understand others’ affective experiences, which has important interpersonal implications.