Objectives: Musculoskeletal chronic pain is a costly public health threat. The aim of our study was to investigate mental health indicators, including self-reported symptoms of depression, sleep disruption, stress, well-being, and quality of life (QoL), among men and women with musculoskeletal chronic pain in a general population. Method: This was a cross-sectional study; a postal questionnaire was mailed to a stratified random sample of 9807 eligible Icelanders retrieved from a national registry, of whom 5906 responded (response rate = 60.2%). Chronic pain conditions included reports of current chronic back pain, chronic neck symptoms, and/or fibromyalgia. Gender-stratified associations of chronic pain conditions with mental health indicators were estimated with logistic regression analyses adjusting for age, income, body mass index (BMI), smoking, education, and residence. Results: We observed higher odds of low satisfaction with life [adjusted odds ratio (ORadj) women 2.0, 95% confidence interval (CI) 1.5-2.6; ORadj men 2.3, 95% CI 1.7-3.1], higher levels of perceived stress (ORadj women 1.7, 95% CI 1.3-2.2; ORadj men = 1.5, 95% CI 1.1-2.1), depressive symptoms (ORadj women 2.4, 95% CI 1.9-3.0; ORadj men 2.8, 95% CI 2.1-3.7), and sleep disruption (ORadj women 2.8, 95% CI 2.2-3.5; ORadj men 2.2, 95% CI 1.5-3.1), and diminished QoL (ORadj women 1.6, 95% CI 1.2-2.1; ORadj men 1.5, 95% CI 1.0-2.1) among individuals with chronic pain compared with those without the condition. Conclusions: Our data indicate that individuals with musculoskeletal chronic pain have increased risk of poor mental health and diminished QoL. Further studies are needed on treatment and preventative measures of a decline in mental health among individuals with chronic pain.