The beard is arguably one of the most obvious signals of masculinity in humans. Almost 150 years ago, Darwin suggested that beards evolved to communicate formidability to other males, but no studies have investigated whether beards enhance recognition of threatening expressions, such as anger. We found that the presence of a beard increased the speed and accuracy with which participants recognized displays of anger but not happiness (Experiment 1, N = 219). This effect was not due to negative evaluations shared by beardedness and anger or to negative stereotypes associated with beardedness, as beards did not facilitate recognition of another negative expression, sadness (Experiment 2, N = 90), and beards increased the rated prosociality of happy faces in addition to the rated masculinity and aggressiveness of angry faces (Experiment 3, N = 445). A computer-based emotion classifier reproduced the influence of beards on emotion recognition (Experiment 4). The results suggest that beards may alter perceived facial structure, facilitating rapid judgments of anger in ways that conform to evolutionary theory.