Chronic musculoskeletal pain (CMP) and coexisting mental health conditions impact young people; however, little is known about their lived and care experiences. In a prospectively registered systematic review with qualitative evidence synthesis (PROSPERO: CRD42022369914), we explored the following: (1) lived physical, psychological, and social experiences; and (2) care experiences/preferences of young people living with CMP and mental health conditions. Inclusion criteria: studies using qualitative methods; participants aged 16 to 24 years with CMP and coexisting mental health condition(s); phenomenon explored included lived and/or care experiences. Seven databases were searched (inception to 19-May-2024), study quality was assessed, data were extracted and analysed thematically, and GRADE-CERQual was used to assess confidence in findings. Twenty-two studies (23 reports) were included (>239 participants, 82% women). Lived experiences yielded 4 themes (9 findings): 2-way relationship between CMP and mental health (2 findings, low to moderate confidence); psychosocial implications of CMP (3 findings, very low-moderate confidence); uncertainty about future (2 findings, low-moderate confidence); coping with CMP and mental health conditions (2 findings, low-moderate confidence). Care experiences/preferences yielded 3 themes (8 findings): navigating healthcare systems (2 findings, moderate confidence); receiving appropriate care (3 findings, very low-moderate confidence); point-of-care experiences and care preferences (3 findings, very low-moderate confidence). Chronic musculoskeletal pain and mental health conditions are interconnected, significantly impacting young people's lives, identities, and socialisation, yet services for CMP and mental health are often inadequate and poorly integrated. The mechanisms and interplay of CMP and mental health require deeper exploration, including how young people may be better supported with personalised, holistic, developmentally and/or life-stage-appropriate integrated care.