In September 1917 "Lightfoot" transferred from the Harwich Force to the Sixth Destroyer Flotilla of the Dover Patrol. "Lightfoot" took part in the First Ostend Raid on the night of 23/24 April 1918, sailing from Dunkirk as part of the escort for the monitors supporting the assault. In April 1918 "Lightfoot" transferred to the 11th Destroyer Flotilla of the Grand Fleet. In July–August, she was refitted at Partick, Glasgow. On 11 November 1918, at the end of the war, "Lightfoot" was recorded as part of the Southern Patrol Force.