Callimachus (c. 303–c. 235 BC) is the foremost scholar-poet of the Hellenistic era. Born in Cyrene, Libya, he came to the court of the Ptolemies in Alexandria, where he composed poetry for the royal family. Contributing to the founding of the Library and the Museum, he was significant for literature, science, and learning. He wrote approximately 800 volumes of poetry and prose on an astounding variety of subjects, including the Pinakes, a descriptive bibliography of the Library's collections in 120 volumes.

His extensive education enriches his poetry, which widely records and recomposes the language and general characteristics of predecessors in pioneering, sophisticated, and expressive ways. The "Callimachian" style, combining knowledge, elegance, and innovation while appreciating the awareness of brevity, clarity, lightness, and charm, served as an important model for later poets, including Catullus, Virgil, Horace, Ovid, and the epigrammatists.

This edition replaces the earlier Loeb editions by A. W. Mair (1921) and C. A. Trypanis (1954, 1958) and presents all that survives of Callimachus and his works, including ancient commentaries (Diegeseis) and scholia. Volume I includes Aetia, Iambi, and lyric poems; Volume II Hecale, Hymns, and Epigrams; and Volume III various epic and elegiac poems, other fragments and testimonia, along with concordances and a general index.

The Greek text is based primarily on the edition by Pfeiffer but has been enriched by papyri published later and by the judgments of subsequent editors. The notes and analysis are fully informed by contemporary research.