Gennadius

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