The house flag of the Federal Steam Navigation Co. Ltd, London. A rectangular white flag with a red cross overall and a blue rectangle in the centre placed over the cross. The flag is made of a wool and synthetic fibre bunting. It has a cotton hoist and is machine sewn. A rope and toggle is attached.

This design was originally the famous house flag of Wigram & Green of Blackwall. A story, probably apocryphal, tells how, in 1824, one of Wigram & Green's ships was ordered to deface their St George's cross flag by the commanding officer at Portsmouth. To avoid confusion with the distinguishing flag of an Admiral of the White, a blue patch from an officer's coat was sewn over the centre.

In 1843 the flag was transferred to Money, Wigram & Sons who retained it until 1884 The flag was transferred to the Federal Steam Navigation Company in 1896 via Allan Hughes of Allport & Hughes who had acquired the company assets. In 1895 Allport Hughes amalgamated into Birt, Potter & Hughes who were financially and managerially involved in the formation of Federal Steam Navigation Co. In 1912 it was taken over by New Zealand Shipping Company but continued to trade as a separate firm. The parent company was taken over by P&O line in 1916. In 1973 the remaining ships of the Federal Steam Navigation co. were transferred to P&O.