Hugh Lyon (19 September 1872 – 1940) was a Scottish trade union leader. Born in Glasgow, Lyon grew up in Falkirk. He left school at the age of eleven to work alongside his father at a local foundry. He joined the Falkirk Central Ironmoulders' Society, a very small union with only twelve members at the Carron Iron Works where he was based. As a result, he was immediately chosen as its shop steward, and rapidly built up membership at the works until all five hundred workers had joined.