Background: There is little focus on adults with cerebral palsy (CP) in research and health care and insufficient knowledge on how to identify and manage pain in this population. Objectives: This systematic review and meta-analysis aimed to determine whether pain prevalence in adults with CP is high and to explore variations in pain prevalence of subgroups, pain locations, pain severity and pain interference. Methods: Potential datasets were identified by experts in the field and literature searches in Embase, MEDLINE, and Cochrane, from January 2000 to October 2016. Included studies had a representative sample of ≥ 25 adults with CP and ≥ 1 pain outcomes. Methodological quality assessment, pain prevalence estimates and logistic regression models for subgroup effects on pain prevalence were conducted. Results: In total, 17 eligible studies were identified from 4584 publications. A meta-analysis was performed with individual participant data from 15 studies totalling 1243 participants (mean [SD] age 34.3 [12.6] years). Overall mean pain prevalence was 70% (95% CI 62–78). Women were more likely to have pain than men (P < 0.001). The odds of pain was increased in adults with gross motor function level II (odds ratio [OR] 1.92, 95% CI 1.22–3.12) and IV (OR 1.77, 95% CI 1.03–4.29). Participants with pain reported pain predominantly in the legs (76%, 95% CI 66–84), and mean pain severity was 3.7/10 (95% CI 2.7–4.7) and pain interference 3.5/10 (95% CI 2.5–4.5). Conclusions: This meta-analysis provides the first reliable pain prevalence estimate in a large international sample of adults with CP. The high prevalence of pain, 70%, suggests that adults with CP should be routinely screened for pain and treated accordingly. The range of measurement instruments used by the included studies emphasizes using common outcome measures specific to pain internationally.