The GPM Ground Validation NCAR Particle Probes OLYMPEX dataset consists of ice water content, particle concentration normalized by bin width, and total particle concentration collected from three instruments flown on the University of North Dakota (UND) Citation aircraft during selected dates in November and December 2015. The PMS Two-Dimensional Cloud probe (2D-C), the SPEC Two-dimensional Stereo probe (2D-S), and two SPEC High Volume Precipitation Spectrometer 3 (HVPS-3) instruments were used in the Global Precipitation Mission (GPM) Olympic Mountains Experiment (OLYMPEX) campaign. All instruments are two-dimensional optical array probes which record images of particles that travel through the sampling area. Data files are available in ASCII format, and browse images are available in PNG format.