Purpose: Evaluate effectiveness of active exercise interventions for improving gross motor activity/participation of school-aged, ambulant/semi-ambulant children with cerebral palsy (CP). Method: A systematic review was conducted following PRISMA guidelines. Five databases were searched for papers including school-aged children with CP, participating in active, exercise interventions with gross motor outcomes measured at the Activity/Participation level. Interventions with previous systematic reviews were excluded (e.g. hippotherapy). Evidence Level and conduct were examined by two raters. Results: Seven interventions (34 studies) met criteria. All studies reported on gross motor function, however, a limited number investigated participation outcomes. Strong positive evidence was available for Gross Motor Activity Training (n= 6, Evidence Level II-IV), and Gross Motor Activity Training with progressive resistance exercise plus additional physiotherapy (n = 3, all Evidence Level II). Moderate positive evidence exists for Gross Motor Activity Training plus additional physiotherapy (n = 2, all Evidence Level II) and Physical Fitness Training (n = 4, Evidence Level II-V). Weak positive evidence was available for Modified Sport (n = 3, Evidence Level IV-V) and Non-Immersive Virtual Reality (n = 12, Evidence Level II-V). There was strong evidence against Gross Motor Activity Training plus progressive resistance exercise without additional physiotherapy (n = 4, all Evidence Level II). Interpretation: Active, performance-focused exercise with variable practice opportunities improves gross motor function in ambulant/semi-ambulant children with CP.