Adolescents with high-functioning Autism Spectrum Disorder (HFASD) experience difficulties with socio-emotional adjustment, including compromised friendships, feelings of loneliness, and depression. Using a sample of 127 adolescents with HFASD and their parents, this study is first to examine: (1) relations between organized activity (OA) involvement and adjustment and (2) whether these relations were moderated by social impairment and executive functions. Results indicated that greater intensity, breadth, and academic OA involvement were associated with fewer depressive symptoms. OA intensity was also associated with less loneliness. For adolescents with better emotional control, greater intensity was associated with better friendship quality. Results suggest that for adolescents with HFASD, more involvement in OA is associated with better socio-emotional adjustment even after accounting for risk factors.