Background Children exposed to maltreatment show neural sensitivity to facial cues signalling threat. However, little is known about how maltreatment influences the processing of social threat cues more broadly, and whether atypical processing of social threat cues relates to psychiatric risk. Methods Forty‐one 10‐ to 14‐year‐old children underwent a social rejection‐themed emotional Stroop task during functional magnetic resonance imaging: 21 children with a documented history of maltreatment (11 F) and 19 comparison children with no maltreatment history (11 F). Groups were matched on age, pubertal status, gender, IQ, socioeconomic status, ethnicity and reading ability. Classic colour Stroop stimuli were also administered in the same paradigm to investigate potential differences in general cognitive control. Results Compared with their peers, children who had experienced maltreatment showed reduced activation in the Rejection versus Neutral condition, across circuitry previously implicated in abuse‐related posttraumatic stress disorder (PTSD), including the left anterior insula, extending into left ventrolateral prefrontal cortex/orbitofrontal cortex; left amygdala; left inferior parietal cortex (STS); and bilateral visual association cortex, encompassing the cuneus and lingual gyrus. No group differences in neural or behavioural responses were found for the classic colour Stroop conditions. Significant negative associations between activity in bilateral cuneus and STS during the rejection‐themed Stroop and higher self‐reported PTSD symptomatology, including dissociation, were observed in children exposed to maltreatment. Conclusion Our findings indicate a pattern of altered neural response to social rejection cues in maltreated children. Compared to their peers, these children displayed relative hypoactivation to rejection cues in regions previously associated with PTSD, potentially reflecting an avoidant coping response. It is suggested that such atypical processing of social threat may index latent vulnerability to future psychopathology in general and PTSD in particular.