Varro was born in or near Reate (now Rieti) to a family thought to be of equestrian rank, and always remained close to his roots in the area, owning a large farm in the Reatine plain, probably near Lago di Ripa Sottile, till his old age.

Politically, he supported Pompey, reaching the office of praetor, after having been tribune of the people, quaestor and curule aedile. He was one of the commission of twenty that carried out the great agrarian scheme of Caesar for the resettlement of Capua and Campania (59 BC).

During the civil war he commanded one of Pompey's armies in the Ilerda campaign. He escaped the penalties of being on the losing side in the civil war through two pardons granted by Julius Caesar, before and after the Battle of Pharsalus. Caesar later appointed him to oversee the public library of Rome in 47 BC, but following Caesar's death Mark Antony proscribed him, resulting in the loss of much of his property, including his library. As the Republic gave way to Empire, Varro gained the favour of Augustus, under whose protection he found the security and quiet to devote himself to study and writing.

He studied under the Roman philologist Lucius Aelius Stilo, and later at Athens under the Academic philosopher Antiochus of Ascalon. Varro proved to be a highly productive writer and turned out more than 74 Latin works on a variety of topics.

Among his many works, two stand out for historians; Nine Books of Disciplines and his compilation of the Varronian chronology. His "Nine Books of Disciplines" became a model for later encyclopedists, especially Pliny the Elder. The most noteworthy portion of the Nine Books of Disciplines is its use of the liberal arts as organizing principles. Varro decided to focus on identifying nine of these arts: grammar, rhetoric, logic, arithmetic, geometry, astronomy, musical theory, medicine, and architecture. Using Varro's list, subsequent writers defined the seven classical "liberal arts of the medieval schools".

The compilation of the Varronian chronology was an attempt to determine an exact year-by-year timeline of Roman history up to his time. It is based on the traditional sequence of the consuls of the Roman Republic, eked out, where that did not fit, by inserting dictatorial and anarchic years. It has been demonstrated to be somewhat erroneous but has become the widely accepted standard chronology, in large part because it was inscribed on the arch of Augustus in Rome; though that arch no longer stands, a large portion of the chronology has survived under the name of Fasti Capitolini.

Varro's literary output was very large; Ritschl estimated it at 74 works in some 620 books, of which only one work survives complete, although we possess many fragments of the others, mostly in Gellius' Noctes Atticae.

Called "the most learned of the Romans" by Quintilian ( Inst. Or. X.1.95), Varro was recognized as an important source by many other ancient authors, among them Cicero, Pliny the Elder, Vergil in the Georgics, Columella, Aulus Gellius, Augustine, and Vitruvius, who credits him (VII.Intr.14) with a book on architecture.

From a modern perspective, one noteworthy aspect of Varro's work is his anticipation of microbiology and epidemiology. Varro warned his contemporaries to avoid swamps and marshland, since such areas "breed certain minute creatures which cannot be seen by the eyes, but which float in the air and enter the body through the mouth and nose and cause serious diseases." (R.R. I.12.2)

Extant works

• De lingua latina libri XXV (or On the Latin Language in 25 Books; of which six survive, partly mutilated)
• Rerum rusticarum libri III (or Agricultural Topics in Three Books)

Known lost works

• Saturarum Menippearum libri CL or Menippean Satires in 150 books
• Antiquitates rerum humanarum et divinarum libri XLI
• Logistoricon libri LXXVI
• Hebdomades vel de imaginibus
• Disciplinarum libri IX (An encyclopedia on the liberal arts, of which the first book dealt with grammar)
• De rebus urbanis libri III
• De gente populi Romani libri IIII
• De sua vita libri III
• De familiis troianis
• De Antiquitate Litterarum libri II (addressed to the tragic poet Lucius Accius; it's therefore one of his earliest writings)
• De Origine Linguae Latinae libri III (addressed to Pompey)
• ???? ?????????? (in at least three books, on the formation of words)
• Quaestiones Plautinae libri V (containing interpretations of rare words found in the comedies of Plautus)
• De Similitudine Verborum libri III (on regularity in forms and words)
• De Utilitate Sermonis libri IIII (on the principle of anomaly or irregularity)
• De Sermone Latino libri V (?) (addressed to Marcellus, on orthography and the metres of poetry)
• De philosophia (cf. Augustine, 'The City of God' xix. 1.)

Most of the extant fragments of these works (mostly the grammatical works) can be found in the Goetz-Schoell edition of De Lingua Latina, p.199-242; in the collection of Wilmanns, p.170-223; and in that of Funaioli, p.179-371.

Varro's own writings

• de Re Rustica (Latin and English at LacusCurtius)
• de Re Rustica (Latin)

Secondary material

• Livius.org: Varronian chronology

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