The Mapping Application for Penguin Populations and Projected Dynamics (MAPPPD) is a web-based, open access, decision support tool designed to assist scientists, non-governmental organizations, and policymakers working to meet the management objectives as set forth by The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) and other components of the Antarctic Treaty System (ATS) (i.e., Consultative Meetings and the ATS Committee on Environmental Protection). MAPPPD was designed specifically to complement existing efforts such as the CCAMLR Ecosystem Monitoring Program (CEMP) and the ATS's Visitor Site Guidelines. The database underlying MAPPPD includes all publicly available (published and unpublished) count data on Emperor, Gentoo, Adélie, and Chinstrap penguins in Antarctica. The structure of the database is designed to allow users to determine the nature and quality of the data they wish to use for management or exploratory purposes, giving stakeholders flexibility for decision making purposes. A front-end web interface located at www.penguinmap.com provides free and ready access to all count data, which can be downloaded in easy-to-use formats thus facilitating transfer of information to Antarctic stakeholders.