Ismaïl Omar Guelleh (Somali:Ismaaciil Cumar Geelle; Arabic:إسماعيل عمر جليه‎) (born 27 November 1947) is the President of Djibouti, in office since 1999.

Guelleh was first elected as President in 1999 as the handpicked successor to his uncle, Hassan Gouled Aptidon, who had ruled Djibouti since independence in 1977. Guelleh was re-elected in 2005 and again in 2011; the 2011 election was largely boycotted by the opposition amid complaints over widespread irregularities. He is often referred to in the region by his initials, IOG. Guelleh has been characterized as a dictator, and his rule has been criticized by some human rights groups.