The house flag of J. & J. Denholm, Greenock. A white rectangular flag with a blue triangle in the centre bearing a white letter 'D'. 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.

The company was founded as a shipbroking business in Greenock in 1866 by James Denholm who was joined three years later by his brother John. In 1872 they bought their first vessel. Denholm Line Steamers Ltd was registered in 1909 running a fleet of tramps. The company ships traditionally had names ending in 'Park'. After heavy losses during the Second World War the company moved into onshore activities, particularly ship management. In 1986 they became involved with fish catching and processing. The Denholm Group remains in business, its activities including shipowning, shipbroking and vessel management.