Gennadius or Gennadios may refer to: People Gennadius of Constantinople (died 471), Patriarch of Constantinople from 458 to 471 Gennadius of Massilia (5th century) Roman historian, best known for his work De Viris Illustribus Gennadius (magister militum Africae), Byzantine general and first exarch of Africa Gennadius (7th century), Byzantine general and exarch of Africa Gennadius of Astorga (9th century), Bishop of Astorga in Spain Gennadius Scholarius (c.1400–c.1473), Patriarch of Constantinople from 1454 to 1464 Georgios Gennadios (1784–1854), Greek man of letters and educationalist Joannes Gennadius (1844–1932), Greek diplomat and bibliophile, son of Georgios Gennadios (Zervos) (born 1937), Greek Orthodox bishop in Italy Gennadios Xenodochof (born 1988), Greek footballer Other Gennadius Library, Athens, Greece, founded by Joannes and named for Giorgios Gennadius (moth), a genus of moth See also Gennady