After being commissioned in December 1918, "Stuart" spent most of her Royal Navy career operating with British forces in the Mediterranean, during which time she was mainly assigned to the 2nd Destroyer Flotilla, operating out of various locations including Malta. In the immediate post war period, amidst the disintegration of the Ottoman Empire and civil war in Russia, "Stuart" was heavily involved in various operations. In 1919–20, "Stuart" saw service in the Black Sea as part of Royal Navy operations during the Allied intervention in the Russian Civil War, being dispatched to Yalta in April 1919 as fighting broke out in the Crimea, and later evacuating troops from the British military mission in March 1920 as Bolshevik forces advanced on Novorossiysk. She also provided assistance to the Greeks during operations against the Turks, reinforcing the Aegean Squadron and escorting troopships during the occupation of Smyrna in May 1919, and the during the landing at Panderma in July 1920. In early 1921, "Stuart" was operating out of Constantinople, where the Allied forces had established an occupation force at the end of the war.