İsmail Hakkı may refer to:

• Ismail Haqqi Bursevi or Bursalı İsmail Hakkı (1653–1725), Ottoman Turkish Muslim scholar, author, poet and composer
• Kurt İsmail Hakkı Pasha (1818–1897), Ottoman field marshal and governor
• İsmail Hakkı (musician) or Muallim İsmail Hakkı Bey (1865–1927), Ottoman composer and musician
• Hakkı Şinasi Erel or İsmail Hakkı Erel (1871–1941), Turkish admiral and politician
• Gümülcineli İsmail or Gümülcineli İsmail Hakkı (1877–1942), Ottoman politician
• İsmail Hakkı Okday (1881–1977), Ottoman military commander
• İsmail Hakkı (army officer) (1883–1923), officer of the Ottoman Army and the Turkish Army
• İsmail Hakkı Baltacıoğlu (1886–1978), Turkish academic and politician
• İsmail Hakkı Uzunçarşılı (1888–1977), Turkish historian and politician
• İsmail Hakkı Berkok (1890–1954), Circassian–Turkish general and politician
• İsmail Hakkı Tonguç (1893–1960), Turkish teacher and educational minister
• İsmail Hakkı Alaç (1911–1989), Turkish footballer
• Hakkı Akansel or İsmail Hakkı Akansel (1924–2016), Turkish politician
• İsmail Hakkı Karadayı (1932–2020), Turkish general
• İsmail Hakkı Sunat (1966–2004), Turkish actor
• İsmail Hakkı Duru (born 1946), Turkish theoretical physicist and mathematician