She was built by Cammell Laird during the First World War, being launched on 14 October 1916 and completing on 21 December that year.

In July 1915, the British Admiralty ordered three Parker-class flotilla leaders (i.e. large destroyers intended to lead flotillas of smaller destroyers in action) under the Sixth Emergency War Construction Programme, Saumarez, Hoste and Seymour, from the Birkenhead shipyard Cammell Laird.

[2] 515 long tons (523 t) of oil fuel were carried, giving a range of 4,290 nautical miles (7,950 km; 4,940 mi) at 15 knots (28 km/h; 17 mph).

[2] The standard anti-submarine armament for flotilla leaders such as Saumarez from June 1916 onwards was two Type D depth charges on chutes, although the number of depth charges tended to increased as the war progressed and the importance of anti-submarine operations grew.

Michael, with the aid of a tug, brought Aspen to safety in Kirkwall, with Saumarez escorting the two ships into harbour.

[16] On 17 November 1917, the Grand Fleet launched a major sortie on German forces in the North Sea - a force of cruisers and destroyers, supported by battlecruisers, and with a squadron of battleships in distant support, was to attack German minesweepers in the Heligoland Bight.

[26] Saumarez remained in reserve most of the rest of her career apart from brief commissionings to take part in exercises, serving as a tender to the training school at Keyham.