İsmail Hakkı may refer to:
People İsmail Hakkı (army officer) (1883–1923), Ottoman and Turkish army officer İsmail Hakkı (musician) (1865–1927), Ottoman composer and musician İsmail Hakkı Alaç (1911–1989), Turkish footballer İsmail Hakkı Baltacıoğlu (1886–1978), Turkish academic and politician İsmail Hakkı Duru (1946–2025), Turkish theoretical physicist and mathematician İsmail Hakkı Karadayı (1932–2020), Turkish general İsmail Hakkı Okday (1881–1977), Ottoman military commander İsmail Hakkı Sunat (1966–2004), Turkish actor İsmail Hakkı Tonguç (1893–1960), Turkish teacher and educational minister İsmail Hakkı Uzunçarşılı (1888–1977), Turkish historian and politician Kurt İsmail Hakkı Pasha (1818–1897), Ottoman field marshal and governor