Background/Objectives: Developmental prosopagnosia (DP) is a neurodevelopmental condition characterised by lifelong difficulties in face recognition. Although substantial work has examined identity processing impairments in DP, less is known about whether these difficulties extend to other aspects of social cognition, including implicit trait judgements from faces. Prior research using Implicit Association Task (IAT) paradigms shows that neurotypical observers can automatically associate facial composites with personality traits such as extraversion. Although some studies report preserved explicit social evaluations in DP, no work has assessed whether individuals with DP can form implicit personality-trait impressions from faces. Methods: The present study examined whether adults with DP (N = 36) exhibit implicit extraversion trait associations using a validated extraversion IAT. Results: Group-level analyses showed a significant IAT effect, indicating sensitivity to congruent face–trait pairings. Single-case analyses using Crawford and Garthwaite’s modified t-test showed that no participant scored significantly below the neurotypical range. Conclusions: These findings suggest that implicit trait-inference processes may remain accessible in DP despite severe identity-recognition impairments, highlighting the potential functional independence of certain social-evaluative mechanisms from those supporting facial identity.