The U.S. Department of Veterans Affairs (VA) has vast amounts of data on U.S. military veterans and their families, caregivers, and survivors. However, much of that trove is not available outside the department, and these data only cover enrolled VA beneficiaries, excluding veterans who are not eligible or have not claimed benefits. In addition, VA holds only a limited scope of data relevant to veteran benefits that does not cover all the data that could be relevant to understanding veteran identity and well-being. To fill in such gaps, those seeking information may turn to scores of additional data collected and maintained by other federal and state government agencies as well as by community and nonprofit organizations. Sources may differ in terms of how veteran status and identity are defined, how the data are presented, who can access the data and how, and the source's strengths and limitations. This report offers a useful guide to existing veteran data sources for users of veteran data, including veteran-serving nonprofit organizations, lawmakers and congressional staffers, government officials, journalists, and researchers. The information presented here will help these users understand (1) how elements of veteran status and identity are defined in different data sources and (2) what kinds of data sources are available that could be used to answer policy-relevant questions about veterans. The information and analyses in this report are drawn from an environmental scan of the various sources of data about veterans and focus group discussions with veteran data stakeholder groups.