Parcel data, or information about individual plots of land, may be used to examine a broad range of social and environmental issues. While analog parcel information has long been available, the move towards digital georeferenced data offers a more readily available means of using detailed structural and land use information. Parcels map onto useful units of analysis such as individuals and households, and serve as the foci of policy institutions tasked with functions such as taxation, schooling, zoning, or public health. The promise of digital parcel data is offset by challenges related to format, availability, maintenance, quality, augmentation, and confidentiality. We examine the use of digital parcel data in research and policy with special reference to land use, public health, education, and environmental applications. We also make recommendations for improving and using parcel datasets.