Sleep is instrumental in the formation of long-lasting memories, including social evaluations and social knowledge. The modification of social evaluations holds profound significance for understanding and shaping societal dynamics. Here, we investigated how sleep could contribute to updating the social evaluation of a person generally perceived as unattractive. We found that, compared with uncued names, auditory cueing (by playing the acoustic name+positive trait pairs) during sleep increased the perceived attractiveness of the mental representations of faces associated with the cued names. Notably, the number of slow oscillations detected during sleep was significantly positively correlated with the attractiveness ratings of the faces corresponding to the cued names. Importantly, a control experiment revealed that mere name exposure without positive traits during sleep did not enhance mental facial representations. These results highlight sleep's active role in updating social evaluations and suggest that sleep-mediated social evaluation updating can be applied in various social contexts.