Hatziioannou or Haji-Ioannou () is a Greek surname. Notable people with the surname include:
Clelia Haji-Ioannou (born 1970/71), Cypriot billionaire Leon Hatziioannou (born 1965), Canadian football player Loucas Haji-Ioannou (1927–2008), Greek-Cypriot shipping entrepreneur Polys Haji-Ioannou (born 1959/60), Cypriot billionaire Stelios Haji-Ioannou (born 1967), British Cypriot billionaire