The present study examined whether the grade point averages (GPAs) of university students could be predicted from appearance-based ratings of their Conscientiousness. Undergraduate participants (N = 249) provided self-reports of their Big Five personality traits and copies of their student transcripts from which their GPAs were obtained. Photographs of these undergraduates were then taken from which their personality traits were judged by unacquainted perceivers. Both aggregated and single perceiver-ratings of Conscientiousness predicted GPA. Aggregated perceiver-ratings predicted GPA incrementally over self-ratings, suggesting that appearance-based judgements of Conscientiousness may contain trait-relevant information beyond the scope of self-reports. These results contribute to a growing literature documenting the validity of appearance-based judgements of personality traits.