Background Early life stress is associated with poorer social functioning. Attentional biases in response to threat‐related cues, linked to both early experience and psychopathology, may explain this association. To date, however, no study has examined attentional biases to fearful facial expressions as a function of early life stress or examined these biases as a potential mediator of the relation between early life stress and social problems. Methods In a sample of 154 children (ages 9–13 years) we examined the associations among interpersonal early life stressors (i.e., birth through age 6 years), attentional biases to emotional facial expressions using a dot‐probe task, and social functioning on the Child Behavior Checklist. Results High levels of early life stress were associated with both greater levels of social problems and an attentional bias away from fearful facial expressions, even after accounting for stressors occurring in later childhood. No biases were found for happy or sad facial expressions as a function of early life stress. Finally, attentional biases to fearful faces mediated the association between early life stress and social problems. Conclusions Attentional avoidance of fearful facial expressions, evidenced by a bias away from these stimuli, may be a developmental response to early adversity and link the experience of early life stress to poorer social functioning.