In World War I, Chetwode served on the Western Front: his brigade helped cover the retreat from the frontier, and checked the pursuing Germans at Cerizy on 29 August 1914. After taking part in the First Battle of Ypres in October 1914, he was appointed General Officer Commanding 2nd Cavalry Division with promotion to temporary major-general on 15 July 1915 and to substantive major-general on 1 January 1916. With the war in Europe become bogged down in trench warfare, Chetwode was lucky to be transferred to the Palestine where he was given command of the Desert Mounted Corps and promoted to temporary lieutenant general with effect from 22 November 1916. He led the corps at Rafa in January 1917 and at the First Battle of Gaza in March 1917. When Edmund Allenby took command of the Allied forces in Palestine in June 1917, Chetwode was promoted to command of XX Corps. He led his corps to military success at the Battle of Beersheba in October 1917 and at the Battle of Jerusalem in November 1917. During the Sinai and Palestine campaign he was mentioned in despatches eight times.