In this data release, we provide data to describe the water quality in Green Lake, Wisconsin, from 1905 to 2020, primarily the constituents for which it is impaired, including near-surface total phosphorus concentrations and metalimnetic dissolved oxygen concentrations, and quantify the water and phosphorus inputs to the lake. We also provide inputs to and outputs from the General Lake Model coupled to the Aquatic Ecodynamics modeling library (GLM-AED) hydrodynamic water-quality model to describe the factors that have caused low dissolved oxygen concentrations in the metalimnion of Green Lake; and quantify how changes in phosphorus loading should affect near-surface total phosphorus and chlorophyll-a concentrations, water clarity, and the minimum dissolved oxygen concentrations in the metalimnion the lake. This data release includes 5 zipped files in child items: (1) Met_Stream_Lake_data, which contains morphology, meteorology, atmospheric deposition, water quality data and mass balance data for the lake; (2) GLM_calibration, which contains inputs to and outputs from the GLM model for which physical parameters in the model were calibrated; (3) GLMAED_Calibration, which contains inputs to and outputs from the GLM-AED model for which physical, chemical, and biological parameters in the model were calibrated; (4) GLMAED_MOMCauses, which contains all of the data needed to run the model to determine the causes of metalimnetic oxygen minima (MOM), and the outputs from the model; and (5) GLMAED_ChangesInPhosphorusLoading, which contains all of the data needed to run the model to determine how dissolved oxygen, near surface total phosphorus, and near-surface chlorophyll-a concentrations respond to changes in phosphorus loading from the watershed, and the outputs from the model.