Background/Objectives: Pain neuroscience education (PNE) has demonstrated efficacy in adults with chronic pain, but the pediatric evidence is still developing, despite its increasingly frequent use. Evidence for the effectiveness of PNE in pediatrics remains fragmented across settings and outcomes, which justifies a systematic evaluation focused on children and adolescents. Methods: Following PRISMA, two reviewers independently screened records (PubMed, Web of Science, PEDro; through 21 July 2025), extracted data, and assessed risk of bias (RoB 2 for randomized controlled trials; NIH/CASP for non-randomized studies). Given the heterogeneity, we conducted a structured narrative synthesis (SWiM) and rated the certainty of evidence with GRADE. PROSPERO: CRD420251062922. Results: Eleven studies met the inclusion criteria. PNE consistently improved pain-related knowledge, with effects maintained at follow-up (moderate certainty); effects on pain intensity, function, and emotional outcomes were small and inconsistent (low certainty), with more favorable patterns when PNE was combined with exercise and/or booster sessions. Digital and gamified formats proved feasible and engaging; parental outcomes showed small improvements where measured. Conclusions: PNE is a promising, low-cost, and scalable component of pediatric chronic pain care, strengthening self-efficacy and adaptive coping. Integration into biopsychosocial, multidisciplinary programs—particularly alongside exercise and family involvement—may optimize outcomes. Larger, standardized trials with long-term follow-up and systematic adverse-event reporting are needed to solidify guidance for clinical practice.