This issue of Past Global Changes Magazine "Building and Harnessing Open Paleodata" showcases the ongoing growth of a rich variety of openly available, globally distributed paleodata. It highlights new scientific, software, funding, and outreach initiatives that harness these open-data resources. Open-data systems are fueling new scientific frontiers, empowering early-career scientists, and enabling the intelligent reuse of data, while encouraging the stewardship of valued data assets. The ultimate goal is to power the next generation of scientists and scientific discovery with an open architecture of scientific data as complex, deep, and interlinked as the Earth system itself.