William Foster & Co Ltd was an agricultural machinery company based in Lincoln, Lincolnshire, England often called "Fosters of Lincoln." The company can be traced back to 1846, when William Foster purchased a flour mill in Lincoln. William Foster then proceeded to start small scale manufacturing of mill machinery and threshing machinery. The mill was converted to an iron foundry by 1856, thus becoming the original Wellington Foundry. By 1899 the works had moved to the Wellington foundry in New Boultham and the original works were then occupied by . During the First World War Fosters built some of the first tanks for the British Army.