While impairments in gross and fine motor skills and executive function are evident from an early age in individuals with autism spectrum disorder (ASD), few studies have explored combined physical activity training and social games as a means of improving these proficiencies in children with ASD. We examined the effects of a 12-week Multilateral Training intervention in 24 children with ASD (M age =9.33, SD = 0.92 years). Participants were matched into pairs, based on age, gender, and autism symptom severity, and we randomly allocated each pair into either an intervention (n = 12) or waitlist control (n = 12) group. Participants in the intervention group performed two 70-minutes sessions per week consisting of a 5-minute warm-up, 40 minutes of motor skills training related to EF (over four progressive levels), 20 minutes of social games, and a final 5-minute cool-down. At baseline and again after the intervention, we administered the Bruininks-Oseretsky Test of Motor Proficiency, 2nd edition (BOT-2), and the Behavior Rating Inventory of Executive Function (BRIEF) to assess all participants’ gross and fine motor skills and EF, respectively. Results showed that the intervention group significantly improved motor skill proficiency (i.e., BOT-2 total motor composite and three motor-area composites) and EF (i.e., BRIEF global EF composite and three EF indices) (p < 0.05; d > 0.84). These findings support the efficacy of Multilateral Training to assist children with ASD with both physical and cognitive/behavioral symptoms.