Epilepsy is a common neurological condition in childhood that is associated with significant social morbidity. Despite a high prevalence of social impairment in children with epilepsy, the factors underpinning social difficulties remain poorly understood and as a result, effective treatments are lacking. Two recent theoretical models of social competence proposed for children with epilepsy, central nervous system conditions, neurodevelopmental and acquired brain disorders have proposed that impairments in social cognition (i.e. Theory of Mind [ToM]) may be related to social impairments in this group. The aims of the thesis were to: (1) study ToM and its relationship to social competence in children and adolescents with genetic generalised epilepsy (GGE) and temporal lobe epilepsy (TLE), and (2) determine whether social impairments could be remediated by targeting ToM. First, we conducted a systematic review and meta-analysis, which revealed significant ToM impairments in adults with epilepsy and a dearth of research in children with epilepsy (Chapter 2). Second, we conducted two empirical studies assessing ToM and social competence in children (8-16 years old) with GGE (Chapter 3) and TLE (Chapter 4); we found evidence of significant ToM impairments that were related to social problems in both epilepsy groups. Third, we developed a novel cognitive behavioural intervention with ToM training for children with epilepsy (Chapter 5), published a study protocol (Chapter 6) and evaluated the intervention in pilot study (Chapter 7); results from the pilot study provided preliminary evidence that the intervention was feasible, acceptable, safe, and a potentially effective way of remediating social problems in our target group. In conclusion, these studies have shown that: (1) children with GGE and TLE have significant impairments in ToM, and associated social problems, and (2) social difficulties can be potentially remediated by targeting ToM impairments in this group.