The Cassopaei (Greek: Κασσωπαῖοι) were a people of ancient Epirus, occupying the coast between Thesprotia and the Ambracian Gulf, and bordering upon Nicopolis; their chief town was Cassope (Κασσώπη). The Periplus of Pseudo-Scylax describes the Cassopaei as living in villages; but they afterwards rose to such power as to obtain possession of Pandosia, Buchaetium, and Elateia. We learn from another authority that Batiae was also in their territory.
- Strabo. Geographica. vii. p.324, et seq. Page numbers refer to those of Isaac Casaubon's edition.
- Smith, William, ed. (1854–1857). "Cassope". Dictionary of Greek and Roman Geography. London: John Murray.
- Stephanus of Byzantium. Ethnica. s.v. Κασσωπία πόλις.
- Periplus of Pseudo-Scylax, p. 12
- Demosthenes, On Halonnesus 33.
- Theopompus ap. Harpocr. s.v. Ἐλάτεια