Background-Cardiovascular disease is the leading cause of death among women in high-income Organization for Economic Co-operation and Development countries. Physical activity is protective for cardiovascular disease. The realities of modern life require working-age women to address work-related, family, and social demands. Few working-age women meet current moderate-to-vigorous-intensity physical activity ( MVPA) recommendations. Given that working-age women spend a substantial proportion of their waking hours at work, places of employment may be an opportune and a controlled setting to implement programs, improving MVPA levels and enhancing cardiometabolic health. Methods and Results-Eight electronic databases were searched to identify all prospective cohort and experimental studies reporting an MVPA outcome of workplace interventions for working-age women ( mean age, 18-65 years) in high-income Organization for Economic Co-operation and Development countries. Risk of bias was assessed using the Cochrane risk of bias tool; quality of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation approach. A qualitative synthesis was performed for all studies, and meta-analyses were conducted where possible. Twenty-four studies met the inclusion criteria; 20 studies were included in the meta-analyses. Workplace interventions significantly increased minutes per week of metabolic equivalents ( 4 studies; standardized mean differences, 2.07; 95% confidence interval [ CI], 1.44 to 2.69), but not minutes per week of MVPA ( 13 studies; standardized mean differences, 0.38; 95% CI, -0.15 to 0.92) or metabolic equivalents per week ( 3 studies; standardized mean differences, 0.11; 95% CI, -0.48 to 0.71). Workplace interventions also significantly decreased body mass ( 7 studies; mean differences, -0.83 kg; 95% CI, -1.64 to -0.02), body mass index ( 6 studies; mean differences, -0.35 kg/m(2); 95% CI, -0.62 to -0.07), low-density lipoprotein ( 4 studies; mean differences, -0.11 mmol/L; 95% CI, -0.17 to -0.04), and blood glucose ( 2 studies; mean differences, -0.18 mmol/L; 95% CI, -0.29 to -0.07). These workplace interventions targeting MVPA levels and known beneficial cardiometabolic health sequelae were of lower quality evidence. Conclusions-Workplace interventions variably improve MVPA levels and related cardiometabolic health sequelae of working-age women in high-income Organization for Economic Co-operation and Development countries. Our findings underscore the need for ongoing research in this area but also increased dissemination of the existing programs and knowledge.