The village of Cornsay lies midway between Lanchester and Tow Law. It is often known locally as Old Cornsay, as nearby is the small pit village of Cornsay Colliery. The old village was first recorded in 1183, when it was known as Corneshow, which probably comes from the Old English for 'Crane's Heugh.

There is very little evidence for early settlement in the area, though this is probably because it has not survived very well, rather than the fact that none occurred. Perhaps the only monument in the village is the small stone building standing over a well built in 1743. Other old buildings, such as the early 19th century almshouses have now disappeared.

Until the 19th century Cornsay was essentially a small farming village. However, in 1868 Cornsay Colliery opened. It worked four thick seams of coal, which were worked by drifts running sideways into the hillside. Most of the coal was turned into coke in the over 270 coke ovens that once stood nearby. The pit also produced fireclay, which was used to make bricks, tiles and sewage pipes. Few remains of the mine can now be seen, except for the heapstead.

Many members of Cornsay Colliery enlisted to fight in the First World War and are commemorated on a plaque that was once in the United Methodist church of the village until the church was demolished. The plaque is now in St. John the Baptist's Church in Quebec.