To systematically review the evidence for intensive mobility training in cerebral palsy (CP) and to determine the minimum effective dose to improve mobility. Randomized controlled trials (RCTs) or quasi-RCTs that included participants with CP, and which used intensive task-oriented training (TOT) mobility interventions and reported mobility outcomes, were included. Five databases were searched; two independent reviewers selected studies and extracted data. The Grading of Recommendations Assessment, Development, and Evaluation system and the Cochrane Risk of Bias 2 tool were used to rate the certainty of evidence at the outcomes level and to determine the risk of bias respectively. Meta-analyses were conducted with clinically homogeneous studies. Threshold dose was analysed through meta-regression. Forty-six RCTs with 1449 participants (mean age range 1 year 2 months to 16 years 4 months) were included. TOT had statistically and clinically significant effects on walking speed (p = 0.001), cadence (p = 0.02), gross motor function (p = 0.03), and functional mobility (p = 0.009) compared with control interventions. The threshold dose was undeterminable owing to the high heterogeneity of studies. TOT may improve walking speed, walking endurance, and balance. Studies with homogeneous samples and outcomes are needed to support clinical recommendations for intensive mobility interventions.