Bartlett-Hayward Company was a metalworking foundry located in Baltimore, Maryland founded in 1837. The company engaged initially in the production of latrobe stoves, but by the end of the nineteenth century, its Pigtown complex was the largest iron foundry in the United States, with a diverse output including cast-iron architecture, steam heating equipment, machine parts, railroad engines and piston rings.
During the peak of cast-iron architecture in the nineteenth century, the company was well known for its ornate building façades, which were shipped nationally. Among their notable projects were their contributions to the Sun Iron Building in Baltimore and the Harper Brothers Building in New York City, together credited as among the first major iron-front buildings in the United States.
In the twentieth century, Bartlett-Hayward expanded to become the country's largest producer of gas holders. During World War I and World War II, the company assembled munitions, artillery carriages and ship propellers for the United States and its allies. The company was acquired, first by McClintic-Marshall Construction Company in 1925, before being sold to Koppers Company in 1927. Absorbed as a directly owned division of Koppers in 1936, the West Baltimore facility remained open in that capacity until the firm left the city about 1980.