The First Cruiser Squadron was a Royal Navy squadron of cruisers that saw service as part of the Grand Fleet during World War I, then later as part of the Mediterranean during the Interwar period and World War II.

In March 1909, then consisting of battlecruisers, it was assigned to the 1st Division of the Home Fleet until April 1912.

This took effect in November 1924 and the squadron was reformed as an enlarged unit of the Mediterranean Fleet under the command of Rear Admiral Arthur Waistell.

In June 1942 the squadron under the commander of Rear-Admiral Louis Keppel Hamilton was assigned to provide distant cover for Convoy PQ 17.

Having been granted the substantive rank of vice admiral on 22 June 1949, Mountbatten became Second-in-Command of the Mediterranean Fleet in April 1950.