The house flag of the Ross Group, Grimsby. A rectangular green flag with a five-pointed white star. The flag is made of a wool and synthetic fibre bunting. It has a cotton hoist and is machine sewn.

John Carl Ross (1901-1986) entered the family fish merchandising business in 1918 when he was demobilized. When his father retired in 1928 the company came under his control. He instigated a number of radical new ideas such as the import of frozen halibut and salmon from North America. The acquisition of a major shareholding in Trawlers Grimsby in 1944 became the foundation of the Ross Group. The Ross Group subsequently acquired several other fishing fleets such as the Queen Steam Fishing Company. In 1956 Ross took over G F Sleight Ltd, which employed 20 of the best trawler skippers in Britain, and began building trawlers in his latest acquisition the Cochrane Shipyards of Selby. These were the famous ' Cat' and 'Bird' class trawlers. At its peak the Ross Group owned the largest fishing fleet in Europe.

Carl Ross left the Ross Group after an acrimonious board room struggle in 1965 and, as a direct result of this, Imperial Tobacco gained control. While Carl Ross was in control Ross Group had diversified into non-fish foodstuffs such as Ross Frozen food. While the non-fish food companies were subject to several further takeovers, the Ross fishing fleet was acquired by British United Trawlers. The Ross House flag was flown for the last time in 1987.