Background: Recent analyses have shown that adverse psychosocial working conditions, such as job strain and effort–reward imbalance, vary by country and welfare state regimes. Another work-related factor with potential impact on health is a poor work–life balance. The aims of this study are to determine the association between a poor work–life balance and poor health across a variety of European countries and to explore the variation of work–life balance between European countries. Methods: Data from the 2010 European Working Conditions Survey were used with 24 096 employees in 27 European countries. Work–life balance is measured with a question on the fit between working hours and family or social commitments. The WHO-5 well-being index and self-rated general health are used as health indicators. Logistic multilevel models were calculated to assess the association between work–life balance and health indicators and to explore the between-country variation of a poor work–life balance. Results: Employees reporting a poor work–life balance reported more health problems (Poor well-being: OR = 2.06, 95% CI = 1.83–2.31; Poor self-rated health: OR = 2.00, 95% CI = 1.84–2.17). The associations were very similar for men and women. A considerable part of the between-country variation of work–life balance is explained by working hours, working time regulations and welfare state regimes. The best overall work–life balance is reported by Scandinavian men and women. Conclusion: This study provides some evidence on the public health impact of a poor work–life balance and that working time regulations and welfare state characteristics can influence the work–life balance of employees.