The trope of “books as friends” has a long history in the Western tradition, including prominent appearances in the personal writings of such figures as Francesco Petrarch, Nicolo Machiavelli, W. E. B. Du Bois, and Virginia Woolf. But, like many things, the first clear attestation of the phenomenon appears in the writings of Cicero: namely, the first letter to Varro of Book 9 of the Familiares, where upon returning to Rome in the wake of Pharsalus, Cicero writes of having been “restored to the favor of [his] old friends, that is to say [his] books” (Fam. 9.1.2 = SB 175 scito enim me, postea quam in urbem venerim, redisse cum veteribus amicis, id est cum libris nostris, in gratiam). This paper collects such references to books as companions, sources of consolation, and sites of affection in Cicero’s works, focusing on the letters and treatises from the period of his philosophical retirement, and shows how Cicero’s thinking about his own personal relationships with old books was shaped by—and in turn shaped—his philosophical project.