The house flag of the Straits Steamship Co. Ltd, Singapore. A rectangular blue flag with a red diamond bearing a white cross overall. The flag is made of a wool and synthetic fibre bunting. It has a cotton hoist and is machine sewn. A rope is attached.

The Straits Steam Navigation Company was formed in Singapore on 20 January 1890 by Dutchman Theodore Cornelius Bogaardt and six other directors. The Company began with five ships, and for the first twenty-five years it operated mainly to the west coast of the Malay Peninsula. It played a considerable part in the exploitation of regions abundant in tin ore deposits, and it also shipped coffee, pepper, rice, rubber and tobacco. Each ship catered for 50 or 60 First Class passengers and approximately 600 deck passengers. The deck passengers were mainly Chinese labourers: until 1928 up to 250,000 arrived annually in Singapore to work in the Peninsula's rubber estates and tin mines.

By 1919 Straits Steamship was the largest line based in Singapore, serving Sabah, Sarawak, Sumatra, Thailand, Burma and both coasts of the Malay Peninsula. Rubber had emerged as the major crop in the region and large estates were founded behind the ports served by the Company. In the inter-war period the company absorbed a number of its competitors, opening up routes to ports such as Rangoon and Bangkok.

At the outbreak of World War II Straits Steamships’ Fleet stood at 51 vessels. Numerous ships and their crews were requisitioned by the Royal Navy. In 1942 Straits vessels were involved in the evacuation of Singapore during the Japanese offensive. Twenty-one ships were destroyed attempting to carry refugees to the safety of Australia and Sri Lanka, and thousands of Straits sailors lost their lives. Also lost were all the company records, and, with Singapore occupied, the company was re-registered in England. During the rest of the war Straits vessels served in all theatres as minesweepers, escorts, patrol boats, hospital ships, guard ships as well as transporting equipment, supplies and troops. By the end of the war the company had lost a total of 38 vessels. The company quickly re-established itself using Navy transport vessels, and when Straits was re-registered in Singapore in 1947 the company fleet was back to its pre-war level.

During the 1960s Straits faced competition from Chinese shipping companies, though this period saw new routes opened to Borneo, and the company continue to upgrade its fleet with new and larger vessels. In 1973 Straits diversified into property which gradually became its core business and in 1989 the company was renamed Straits Steamship Land. The shipping side of the company was separated and named Steamers Maritime Holdings Limited. In 1997 Straits was taken over by the Keppel Group.