The National Institute for Health and Welfare (THL) is a research and development institute under the Finnish Ministry of Social Affairs and Health.

THL works to promote the well-being and health of the population, prevent diseases and social problems, and develop social and health services.

THL is the statutory statistical authority in health and welfare and maintains a strong knowledge base within its own field of operations. THL is also responsible for the application of this knowledge.

THL has a wide range of tools to carry out its responsibilities: research, follow-up and evaluation, development, expert influence, official tasks as well as international co-operation.

THL seeks to serve the broader society in addition to the scientific community, actors in the field and decision-makers in central government and municipalities.