Groundwater samples collected between 2016 and 2018 from 56 shallow (<40 m depth) monitoring wells in Long Island, N.Y., were collected in support of the Long Island Pesticide Pollution Prevention Strategy. Each well was sampled at least once and analyzed for over 200 pesticides and pesticide degradates as part of this study. Results presented here also include field and inorganic analysis data, as well as neonicotinoid (LC9045) and glyphosate pesticide data collected from select monitoring wells. Data collection and analysis was supported by the New York State Department of Environmental Conservation, Suffolk County Department of Health Services, and Long Island Commission for Aquifer Protection. The results presented in this data release are samples that were collected and analyzed by the U.S. Geological Survey (USGS). Groundwater samples were analyzed by the USGS National Water Quality Laboratory (NWQL), in Denver, CO and the Organic Research Laboratory, in Lawrence, KS. This data release includes all method descriptions and quality assurance and quality control criteria in the metadata.