Children with ASD and children with ID face numerous challenges in social and emotional functioning. The aim of this study is to explore differences in social and emotional competencies between children with ASD, children with ID and children with comorbid ASD/ID. Methods: Parents (N = 177) assessed the social and emotional competencies of elementary school-aged children with ASD (N = 50), children with ID (N = 84), and children with comorbid ASD/ID (N = 43) using the Devereux Student Strengths Assessment (DESSA). DESSA measures 8 key social and emotional competencies. In our study, no differences in social and emotional competencies were found between children with ASD and children with ID. Children with comorbid ASD/ID did not differ from children with ASD, but compared to children with ID, parents rated their self-awareness, social awareness, relationship skills, and optimistic thinking as significantly lower. The results were discussed considering the type of school attended by the children, the level of intellectual disability of children with ID, and the complexity of functioning of children with ASD. All three groups of children require tailored interventions for social and emotional learning to support their functioning in daily activities at home, at school and in peer groups.