"Overeating" is a significant public health concern, but little is known about how lay people conceptualize overeating. This study explored participants' conceptions of overeating. Participants were 175 university students and 296 community members (56% women) who were asked to rate the extent to which several statements reflected the concept of "overeating" (1 = Does not capture the meaning at all; 7 = Captures the meaning perfectly). Results showed that eating outside of hunger was viewed as being most strongly linked to the conceptualization of overeating; mindless eating, eating more than some normative amount, and a lack of restriction were all moderately linked to the conceptualization of overeating; and the quality of the food/eating style was rated as least relevant to the conceptualization of overeating. Participants with a higher BMI, participants who perceived themselves as fat, restrained eaters, and participants with an indication of eating pathology rated all of the constructs as more relevant to the concept of overeating than did their respective counterparts, but their overall pattern of responding was the same. The present research provides some initial insights into people's thoughts on what it means to "overeat," which is important given that simply believing that one has overeaten (regardless of the actual amount consumed) can have adverse psychological and behavioral consequences. These insights provide an avenue for future research to explore whether lay conceptions could be more adaptively reshaped to reduce the negative effects of perceived overeating.