The XVIII Corps of the Ottoman Empire (Turkish: 18 nci Kolordu or On Sekizinci Kolordu) was one of the corps of the Ottoman Army. It was formed during World War I.
On October 29, 1912, the corps was structured as follows:
The corps was formed as the Right Wing Group of the Mahmut Kâmil Pasha's Third Army on June 7, 1915 and commanded by Halil Bey. In a rearrangement of operational field commands, Mahmut Kâmil Pasha redesigned this unit as the Provisional Halil Corps.
On September 20, 1915, the Provisional Halil Corps was re-designated as the XVIII Corps of the Ottoman Army. In late Summer 1915, the corps was structured as follows:
In January 1916, the corps was structured as follows:
In August 1916, the corps was structured as follows:
In December 1916, the corps was structured as follows:
In August 1917, January 1918, the corps was structured as follows:
In November 1918, the corps was structured as follows: