acsearch.info is an auction database containing numismatic auctions from various renowned international auction houses. The database in part goes back more than 17 years and contains pictures, descriptions and realized prices in several currencies.

This is a great and very comprehensive list of ancient coins. It is particularly useful for identifying Roman Imperial coins. 

CoinHoards is a component of the National Endowment for the Humanities funded Hellenistic Royal Coinages project developed by the American Numismatic Society (ANS). An innovative research resource, CoinHoards provides primary data and other information on 2,387 hoards of coins produced by Greeks and other non-Roman peoples in the Mediterranean and adjacent regions between ca. 650 and 30 BCE. In addition to a basic description, users will find on the page devoted to each hoard mapping tools for the findspot and mint(s) where the coins found in the hoard were produced, bibliographical references, and a list of the hoard contents. Where possible, each type of coin listed is linked to a typological description, such as those found on PELLA, Seleucid Coins Online, and Ptolemaic Coins Online. Additional links are provided where possible to relevant resources associated with the hoard, which might include the MANTIS record of individual coins from the hoard held in the ANS collection, ANS publications, the notebooks of Edward T. Newell, and associated correspondence, notes, and archival material.

Hellenistic Royal Coinages (HRC) is a National Endowment for the Humanities funded project based at the American Numismatic Society in New York City. HRC is a web-based resource for users to learn about, research, and conduct different types of analyses on the coinages produced by the different dynasties and rulers of the ancient Mediterranean and Near East during the Hellenistic period (ca. 323–31 BC). These include the coins struck by (and in the name of) Alexander the Great and those struck by his successors, such as the Seleucids in the Near East and the Ptolemies in Egypt.

Coinage of the Roman Republic Online (CRRO) aims to provide in effect an online version of Michael Crawford's 1974 publication Roman Republican Coinage (RRC), which is still the primary typology used for the identification of Roman Republican coin types. Since its publication in 1974 there have been significant revisions to the dating of the series following the discovery of new hoards, but no attempt has been made to reflect these or make any other amendments to the published typology at this stage. The descriptions for these coins are based on the typology set out in RRC, but have been modified to meet the standards of the British Museum’s collection management system. Additional types not in the British Museum’s collection were added to this database by Richard Witschonke of the ANS.

The Roman Provincial Coinage project embodies a new conception of Roman coinage. It presents for the first time an authoritative account of the coins minted in the provinces of the empire and shows how they can be regarded as an integral part of the coinage minted under the Roman emperors.

The aim of this major research project is to produce a standard typology of the provincial coinage of the Roman Empire. This represents the first systematic treatment of the civic coinage at the height of the Roman empire. The material presented is an invaluable source of infor­mation for imperial portraiture and titulature, the response of the cities to the establishment of a new political order under the Roman empire, the way the government controlled the provinces, the internal history of the cities, and the role of the provincial coinage in the economy of the Roman empire as a whole. It will thus not only meet the needs of numismatists but will also be an essential reference book for historians, epigraphists, archaeologists and other students of the Roman empire.

The Colosseo Collection has been in continual development for over 15 years with new coins added regularly, focusing on the first millennium of coinage.

In addition to art and historical significance, pedigree is of particular focus: the Collection includes coins from the famed collections of Kunstfreund, Pozzi, Biaggi, Jameson, Weber, Montagu, Magnaguti, Lockett, Apostolo Zeno, d'Este, Evans, Moretti, and many more.

The mission of the Archives is to serve as a centralized resource for historical information about the Society. The ANS Archives fulfills this mission by: 

• collecting, preserving, and making accessible the historical records of the Society;

• using these records to promote to key audiences the Society's heritage of success; and

• supporting the Society's staff in their roles as scholars and administrators.

The records housed in the ANS Archives document the history and development of the Society, its collections, exhibitions, and programs, as well as the contributions of individuals and groups associated with the Society — they are unique and irreplaceable assets. 

In short, the ANS Archives serves as the Society's "institutional memory."

Nomisma.org is an international, collaborative project to provide stable digital representations of numismatic concepts according to the principles of Linked Open Data (LOD). These take the form of HTTP URIs that also provide access to reusable information about those concepts, along with links to other resources. The Nomisma.org community maintains a formalized RDF Ontology and a data model for encoding concepts, coins, typologies, hoards, and other types of numismatic objects as LOD.

The information made available by Nomisma.org has been provided by a wide community of scholars and institutions. All concepts published by Nomisma.org domain are openly accessible with a CC-BY license. See the Datasets page for further license statements for partner contributions to the Nomisma.org LOD ecosystem.

Founded in 1858, The American Numismatic Society is dedicated to the study and appreciation of numismatics and has assembled a permanent collection of more than 800,000 coins, monetary objects, medals, and other related items dating back to 2000 BCE. The specialized library contains approximately 100,000 books, documents, and artifacts that are among the finest of such resources. Together, they comprise one of the most extensive numismatic holdings in the world. The Society is also a global leader and innovator in the development of digital numismatic resources and is one of the largest publishers of scholarly numismatic research, enjoyed by its members, fellows, and the public at large.

The Ancient Coin Collectors Guild is a non-profit organization committed to promoting the free and independent collecting of coins from antiquity.

The goal of the guild is to foster an environment in which the general public can confidently and legally acquire and hold any numismatic item of historical interest regardless of date or place of origin.

ACCG strives to achieve its goals through education, political action, and consumer protection.

This forum was begun after some disillusionment of the Ancient Coin collecting community from CoinTalk with that platform. As such, a great deal of the discussion is about Ancient coins, although all numismatics are welcome.