İsmail Hakkı may refer to:
- Bursalı İsmail Hakkı or İsmail Hakkı Bursevî (1653-1725), Ottoman lyricist, Sufi sheikh of the Jelveti Tekke in Bursa. Penned countless works on Tasavvuf, Islamic philosophy, morality and Tefsir.
- İsmail Hakkı Baltacıoğlu (1886–1978), Turkish academic and politician
- İsmail Hakkı Bey (1883-1923), officer of the Ottoman Army and the Turkish Army
- İsmail Hakkı Duru (born 1946), Turkish theoretical physicist and professor of Mathematics
- İsmail Hakkı Karadayı (1932–2020), Turkish general
- İsmail Hakkı Uzunçarşı (1888–1977), Turkish historian and politician