Bowersock, G.W., Peter Brown, and Oleg Grabar, eds. Late Antiquity: A Guide to the Postclassical World. Cambridge, MA and London, 1999. Ref. DE5.L29 1999
Eleven topical essays on "late antiquity" (defined as roughly 250-800 C.E.) and an "Alphabetical Guide." The editors distinguish their "guide" from an encyclopedia, a dictionary, or a lexicon by claiming that they do not intend to provide exhaustive coverage of "late antiquity" but aim to "provoke thought" and to "encourage readers to travel in new directions." See Jenkins, Classical Studies, p. 44 (#130).
Cancik, Hubert, and Helmuth Schneider, eds. Brill's New Pauly: Encyclopedia of the Ancient World. 15 vols. Leiden; Boston: Brill, 2002-2010. Ref. DE5 .P3332 2002
This translation of Der neue Pauly: Enzyklopädie der Antike (DE5 .P333 1996) is the "largest classical dictionary/encyclopedia available in English" (Jenkins, Classical Studies, p. 44f. (#134). This is an updating and enlargement of Der Kleine Pauly (see below) but does not entirely supersede the much larger Pauly's Realencyclopädie der Classischen Altertumswissenschaft (see below).
Gagarin, Michael and Elaine Fantham, eds. The Oxford Encyclopedia of Ancient Greece and Rome. 7 vols. 2010. Online only
Contains 1100 articles covering the ancient Mediterranean--Greek, Hellenistic, Roman--world. Not as exhaustive as Brill's New Pauly (see above).
Hornblower, Simon and Antony Spawforth, eds. The Oxford Classical Dictionary. 4th ed. Oxford; New York: Oxford University Press, 2003. Ref. DE5.O9 2012
The standard, one-volume English language reference on the classical world. Beginning with the 3rd edition (2003), the dictionary has been significantly revised and expanded. Noteworthy features are an emphasis on thematic articles such as "apocalyptic literature," "asceticism," "disease," "economy," "homosexuality," "motherhood," "oriental cults and religion," etc. and interdisciplinary articles such as "literary theory and classical studies" and "Marxism and classical antiquity." See Jenkins, Classical Studies, p. 47f. (#142).
Nicholson, Oliver, ed. The Oxford Dictionary of Late Antiquity. 2 vols. Oxford, UK: Oxford University Press, 2018 Ref. D54.O946 2018
Covers the "history, religion, literature, and physical remains of the half-millenium between the mid-3rd and the mid-8th century AD in Europe, North Africa, and Western and Central Asia." Includes lists of "Bishops of the Five Great Patriarchal Sees" (Alexandria, Antioch, Constantinople, Jerusalem, Rome) at the end of vol. 2.
Temporini, Hildegard, and Wolfgang Haase, eds. Aufstieg und Niedergang der Römischen Welt: Geschichte und Kultur Roms im Spiegel der neueren Forschung. Berlin: W. De Gruyter, 1972- . DG209.A9
Multi-volumed set consisting of three parts. The first, complete in 4 volumes, covers Rome form its origins to the end of the republic. The second part deals with the principate (the early empire) and now stands at 60+ volumes. The third part, covering late antiquity, has yet to begin. Contains review, survey and bibliographic articles; many present original research. Lack of an overall index or table of contents for the entire set makes using this difficult. There is a searchable index at http://www.cs.uky.edu/~raphael/scaife/anrw.html and lists of tables of contents for published and forthcoming volumes at http://www.bu.edu/ict/anrw/index.html. See Jenkins, Classical Studies, p. 105f. (#315).
Ziegler, Konrat, and Walther Sontheimer. Der Kleine Pauly: Lexikon der Antike auf der Grundlage von Pauly's Realencyclopädie der classischen Altertumswissenschaft. 5 vols. Stuttgart: Alfred Druckenmuller, 1964-1975. Ref. DE5.K64
This updated, revised and much abridged version of Pauly's Realencyclopadie (see below) has been mostly superseded by Brill's New Pauly: Encyclopedia of the Ancient World (see above) but can be helpful since it often indicates where articles on a particular subject may be found in the original, complexly organized Realencyclopadie. See Jenkins, Classical Studies, p. 55 (#165).
Pauly, August Friedrich von. Pauly's Realencyclopädie der Classischen Altertumswissenschaft. Neue Bearbeitung unter Mitwirkung zahlreicher Fachgenosen herausgegeben von Georg Wissova. Series I, 24 vols.; Series II, 18 vols. Stuttgart: J.B. Metzler, 1893-1972.
Paulys Realencyclopädie der Classischen Altertumswissenschaft. Supplement. 15 vols. Stuttgart: J.B. Metzler, 1903-1978.
Gartner, Hans, and Albert Wunsch. Paulys Realencyclopädie der classischen Altertumswissenschaft: Neue Bearbeitung begonnen von Georg Wissova fortgefuhrt von Wilhelm Kroll und Karl Mittelhaus... Register der Nachtrage und Supplemente. Munchen: Alfred Druckenmuller, 1980.
Erler, Tobias et al. Paulys Realencyclopädie der Classischen Altertumswissenschaft: Gesamtregister I: Alphabetischer Teil. Stuttgart; Weimar: J.B. Metzler, 1997. DE5 .P33 1997 Index
Paulys Realencyclopädie is the fundamental, albeit in many ways dated, reference work for classical studies. The organization of the eighty-three volume set is complex; the set is best approached either through the index by Gartrner and Wunsch or the alphabetical list of entries in Erler's et al, Gesamtregister, available also on CD-ROM in the Vatican Film Library. See Jenkins, Classical Studies, p. 51f. (#155-156).