This study has examined the link between social information processing (SIP) and socio-emotional regulation (SER) in 45 children with intellectual disability (ID) and 45 typically developing (TD) children, matched on their developmental age. A Coding Grid of SER, focusing on Emotional Expression, Social Behaviour and Behaviours towards Social Rules displayed by children in three dyadic contexts (neutral, competitive or cooperative) was applied. Correlational analyses highlighted specific “bi-directional” links between some abilities in SIP and in SER, presenting between-groups partial similarities and dissimilarities that allowed discussing the developmental delay versus difference hypotheses in ID children. Cluster cases analyses identified subgroups with variable patterns of links. In both groups, the SIP and some categories of SER varied depending on developmental age.