The First Fleet was a formation of the Royal Navy that briefly existed before the First World War from 1912 to 1914.

The First Fleet was formed on 31 July 1912, with the Commander-in-Chief Home Fleets in direct command of it;[1] a vice admiral commanded the Second and Third Fleets.

The numbered fleets during this period had different levels of battle readiness; ships of the First Fleet ships were in full commission.

[2] The First Fleet included four destroyer flotillas under Captain Cecil Lambert.

[3] Captain Reginald Tyrwhitt took over the command of the destroyer flotillas in December 1913.