The Archaeological Institute of America (AIA) provides an extensive list of digital resources on its Fieldnotes webpage, including an overview of several excavations, surveys, and other research initiatives.
ARIADNE brings together and integrates existing archaeological research data infrastructures so that researchers can use the various distributed data sets and new and powerful technologies as an integral component of the archaeological research methodology.
The American School of Classical Studies at Athens (ASCSA) is the official link between American archaeologists and classicists and the Greek Archaeological Service of the Ministry of Culture. Broadly responsible for all American excavations in the country, the ASCSA has two home excavations—Ancient Corinth and the Athenian Agora. The School provides data on both sites, as well as links to several other affiliated excavations in Greece.
The aim of the site is to provide a database of excavations since 2000, providing a record in English and in the local language for each season.
Kelsey/University of Michigan Field Projects
The Kelsey Museum at the University of Michigan currently sponsors five active field projects: in Italy, Greece, Turkey, Egypt, and Sudan. The research portal includes links to each excavation's websites and online reports, along with information on past field projects across the Mediterranean and Middle East.
Peripleo is a search engine to data maintained by partners of Pelagios Commons, a digital humanities initiative aiming to foster better linkages between online resources documenting the past. Most of our partners publish information about ancient places and physical objects, such as archaeological finds. But Pelagios Commons is growing, and we are beginning to include data about people, time periods, and even geo-tagged literature, or data transcribed from historic maps.
Pleiades is a community-built gazetteer and graph of ancient places. It publishes authoritative information about ancient places and spaces, providing unique services for finding, displaying, and reusing that information under open license.
The Princeton Encyclopedia of Classical Sites
This open-access database, by Perseus, derives from the original 1976 encyclopedia. Spanning across Europe, the Mediterranean, and the Middle East, its 2,800 entries were written by 375 scholars, many of whom have worked at the sites they describe. As an alternative, you can access the PDF of the encyclopedia through JSTOR, which requires institutional login.