The GPM Ground Validation Upper Air Radiosonde OLYMPEX dataset was collected from October 28, 2015 through January 16, 2016 during the GPM Ground Validation Olympic Mountain Experiment (OLYMPEX) held on the Olympic Peninsula in the Pacific Northwest of the United States. Radiosondes were released from 5 locations: 3 in US - KSLE, KUIL, and NPOL site; and 2 in Canada - ECCC instrument site and CYZT. A total of 651 radiosondes were launched and collected during OLYMPEX from these sites. In addition, Level 4 dropsonde data were reprocessed to match the Level-4 data format and content of the radiosonde files and is also provided here. The dropsondes were released from the NASA DC-8 aircraft during specific flights in December 2015 and are published as the AVAPS dataset. This Upper Air Radiosonde dataset contains Level 0 through Level 4 data containing dew point temperature, pressure, air temperature, relative humidity, horizontal wind speed, vertical wind speed, wind direction, rise or drop rate, and geopotential height measurements. The data files are available in ASCII, ASCII-EOL, and netCDF-3 formats, as well as Skew-T and time series plots in PNG format. The lower level datasets (Level 0 raw data through Level 2 data) are only available upon request from the NASA GHRC DAAC.