Archived qualitative data are a rich and unique source of evidence on the human condition, enabling researchers of the future to exploit data collected from social research of the past. This entry sets about describing a potted history and evolution of current practices in archiving and reusing qualitative data. First, it looks at where one can find archived sources of qualitative data and then discusses the current professional practice of “data archiving” with discoverability, long-term access, and preservation in mind. The next part of the entry demonstrates how one can best prepare, describe, and document a data collection from a research project to confront issues surrounding various theoretical, methodological, ethical, and challenges relating to reusing data. The final part provides two examples of how data collections have been prepared for archiving are provided, drawn from the UK Data Service, a national repository that holds over 1,000 sets of qualitative data available for reuse.