The Battle of Wadi, occurring on 13 January 1916, was an unsuccessful attempt by British forces fighting in present-day Iraq during the First World War to relieve beleaguered forces under Sir Charles Townshend then under siege by the Turks at Kut-al-Amara.
Pushed by regional British Commander-in-Chief Sir John Nixon, General Fenton Aylmer launched an attack against Turkish defensive positions on the banks of the Wadi River. The Wadi was a steep valley of a stream that ran from the north into the River Tigris, some 6 miles (9.7 km) upstream towards Kut-al-Amara from Sheikh Sa'ad. The attack is generally considered as a failure, as Fenton managed to capture the Wadi, but at a cost of 1,600 men, which led to Townshend's submission, along with 10,000 of his men, in the largest single surrender of British troops up to that time. However, the British recaptured Kut in February 1917, on their way to the capture of Baghdad the following year.