Abdallah ibn Qais (Κάϊσος, Kaisos and Ἀβδελᾶς, Abdelas in Greek sources) was an Ummayad military leader active against the Byzantine Empire in the 670s. In ca. 672/673 he led a raid into Cilicia and Lycia, and wintered there before returning to Syria. In 674/675, by which time, according to al-Tabari, he was admiral-in-chief of the Ummayad navy, he led a raid against the island of Crete along with general al-Fadl ibn Ubaid.
Winkelmann, Friedhelm; Lilie, Ralph-Johannes et al. (1999), "‘Abdallāh ibn Qais (#12)", Prosopographie der mittelbyzantinischen Zeit: I. Abteilung (641–867), 1. Band: Aaron (#1) – Georgios (#2182) (in German), Walter de Gruyter, pp. 4–5, ISBN978-3-11-015179-4