The house flag of the Orkney Steam Navigation Co., Kirkwall. A rectangular flag divided diagonally into four broad white and five narrow red stripes. A rope and toggle are attached.

The Orkney Steam Navigation Co was an inshore passenger and cargo company operating out of Kirkwall, Orkney, running local services to neighbouring islands including the Northern Isles. The company was founded in 1868 to operate the steamer ‘Orcadia’ built by Readhead Softley & Co of South Shields. During the 19th century it also earned considerable sums from salvage work. For most of its history it ran only one or two vessels. In 1962 the company was reformed as the Orkney Islands Shipping Co to operate a new motor vessel also named ‘Orcadia’. It took over two steamers from the original firm. The last of these SS ‘Earl Sigurd’ was broken up in 1969. The company is still in business, from 1995 as Orkney Ferries Ltd. The Orkney Islands Council assumed responsibility for the inter islands ferry service from 1987.