NARSTO (formerly North American Research Strategy for Tropospheric Ozone) was a partnership among government, private industry, and research organizations in Canada, the United States and Mexico that was dedicated to improving the management of air quality in North America. Its primary mission to coordinate and enhance policy-relevant scientific research and assessment of tropospheric pollution behavior; its activities input for science-based decision-making and determination of workable, efficient, and effective strategies for local and regional air-pollution management. Data products from local, regional, and international monitoring and research programs are available.

The NARSTO organization, having met the goals of its 1999 charter, was disbanded as of December 31, 2010