The National Union of Cokemen and By-product Workers was a trade union representing workers involved in turning coal into coke at collieries in Great Britain.

It originally had 1,225 members, but this rose quickly to reach 2,382 in 1915.

In 1916, it merged with the Durham Cokemen and Labourers' Union, to form the "National Union of Cokemen and By-product Workers".

[1] The union affiliated to the Miners' Federation of Great Britain in 1919.

[1] The union was still in existence in 2014, by which time it had just ten members remaining.