The STIX Ground Analysis Software (STIX-GSW) is the IDL-based analysis package for the Spectrometer/Telescope for Imaging X-rays (STIX), a hard X-ray instrument onboard ESA's Solar Orbiter mission. STIX observes solar flares and energetic particle events in the 4–150 keV energy range, providing imaging spectroscopy of high-energy solar phenomena. STIX-GSW provides the scientific community with tools to access, process, and analyse STIX observational data. Core capabilities include: spectral analysis and integration with OSPEX; X-ray image reconstruction using visibility-based algorithms (CLEAN, MEM, EM, uv-smooth); aspect and pointing correction; livetime and detector response corrections; and conversion of telemetry data to calibrated science products. The software is distributed as part of SolarSoftware (SSW). A Python companion package, stixpy, is maintained separately at https://github.com/TCDSolar/stixpy.