Child sexual abuse within institutional settings has been a major concern for governments around the world for many years. Consequently, prevention policies have been developed, and institutional child abuse laws have been strengthened in many jurisdictions. Legislation is important to prevent reoffending, however, the majority of childhood sexual abuse remains unreported and undetected. While awareness of the failings of institutions to properly identify and respond to child abuse has grown in recent years, barriers to reporting institutional abuse remain understudied, impacting the ability to prevent abuse. One possible reason that prevents workers from identifying and reporting child sexual abuse is that their judgements are vulnerable to stereotypes and unconscious biases about who perpetrates and is victimised by sexual crimes and what constitutes warning signs of sexually abusive behaviours. Research in psychology provides key insights into human reasoning processes that can lead to bias, so workers fail to identify, respond and prevent grooming and child abuse in an organisational context. This paper reviews what is known about the development and maintenance of stereotypes and unconscious bias, their role in institutional sexual abuse, and concludes with a discussion of measures that can be taken to mitigate unconscious bias to prevent child abuse.