The GPM Ground Validation Micro Rain Radar (MRR) OLYMPEX dataset was gathered during the Global Precipitation Measurement (GPM) Ground Validation OLYMPEX field campaign held at Washington’s Olympic Peninsula from October 31, 2014 through May 22, 2016. The dataset contains measured and derived data from MRR instruments placed in four separate locations within the study region. The MRR is a Biral/Metek 24 GHz (K-band) vertically oriented Frequency Modulated Continuous Wave (FM-CW) radar that measures signal backscatter from which Doppler spectra, radar reflectivity, Doppler velocity, drop size distribution, rain rate, liquid water content, and path integrated attenuation are derived. Data files are available in ASCII data format.