Obesity is a risk factor for fibromyalgia in adults, but whether a similar relationship exists in children is uncertain. This study examined whether obesity is associated with reporting of musculoskeletal pain, including chronic regional pain (CRP) and chronic widespread pain (CWP), in adolescents, in a population-based setting. A pain questionnaire was administered to offspring of the Avon Longitudinal Study of Parents and Children at age 17, asking about site, duration, and pain intensity, from which participants with different types of musculoskeletal pain were identified. Relationships between obesity and pain were examined by calculating odds ratios stratified by gender and adjusted for socioeconomic status as reflected by level of maternal education. A total of 3376 participants (1424 boys) with complete data were identified, mean age 17.8; 44.7% of participants reported any pain within the last month lasting 1day or longer; 16.3% reported lower back pain, 9.6% shoulder pain, 9.4% upper back pain, 8.9% neck pain, 8.7% knee pain, 6.8% ankle/foot pain, 4.7% CRP, and 4.3% CWP; 7.0% of participants were obese. Obesity was associated with increased odds of any pain (odds ratio [OR] 1.33, P=.04), CRP (OR 2.04, P=.005), and knee pain (OR 1.87, P=.001), but not CWP (OR 1.10, P=.5). Compared with non obese participants, those with any pain, knee pain, and CRP reported more severe average pain (P<.01). Obese adolescents were more likely to report musculoskeletal pain, including knee pain and CRP. Moreover, obese adolescents with knee pain and CRP had relatively high pain scores, suggesting a more severe phenotype with worse prognosis. Copyright © 2012 International Association for the Study of Pain. All rights reserved.