Passage 10.38.10
κληθῆναι δὲ ἀπὸ γυναικὸς ἢ νύμφης τεκμαίρομαι τὴν πόλιν, ἐπεὶ ἐπὶ Ναυπάκτῳ γε οἶδα εἰρημένον ὡς Δωριεῖς οἱ ὁμοῦ τοῖς Ἀριστομάχου παισὶ τὰ πλοῖα αὐτόθι ἐποιήσαντο, οἷς ἐς Πελοπόννησον ἐπεραιώθησαν· καὶ ἀντὶ τούτου γενέσθαι τὸ ὄνομα τῷ χωρίῳ φασί. τὰ δέ μοι Ναυπακτίων, ὡς τοῖς ἐς Ἰθώμην ἀποστᾶσιν ὁμοῦ τῷ σεισμῷ τῷ ἐν Λακεδαίμονι Ἀθηναῖοι Ναύπακτον ἐνοικῆσαί σφισιν ἔδοσαν ἀφελόμενοι τοὺς Λοκροὺς καὶ ὡς τοῦ Ἀθηναίων ὕστερον πταίσματος τοῦ ἐν Αἰγὸς ποταμοῖς Λακεδαιμόνιοι τοὺς Μεσσηνίους ἐδίωξαν καὶ ἐκ τῆς Ναυπάκτου, τάδε μὲν ἐπεξῆλθέ μοι καὶ ἐς πλέον ἡ Μεσσηνία συγγραφή· ἐκλιπόντων δὲ ὑπὸ ἀνάγκης τῶν Μεσσηνίων, οὕτως οἱ Λοκροὶ συνελέγχθησαν αὖθις ἐς τὴν Ναύπακτον.
I infer that the city took its name from a woman or nymph, since concerning Naupactus, at least, I know it is said that the Dorians who were with the sons of Aristomachus built ships there, by means of which they crossed over into the Peloponnese; and for this reason, they say, the place received its name. As to the history of the inhabitants of Naupactus—that the Athenians settled here those who had revolted to Ithome at the time of the earthquake in Lacedaemon, having taken Naupactus away from the Locrians; and that afterward, when the Athenians suffered their defeat at Aigospotamoi, the Spartans drove the Messenians out of Naupactus as well—all these matters I have fully related in my account of Messene. When the Messenians were thus forced to abandon the city, the Locrians once more regained possession of Naupactus.