Bolton Union Mill was a cotton spinning mill in Halliwell, Bolton, Greater Manchester. It was built in 1875 and 1880. It was taken over by the Lancashire Cotton Corporation in the 1930s and brought back into production. Subsequently, it passed to Tootals and in 1964. Production finished in 1967. The building is still standing. It has 15,466 m2 (166,470 sq ft) of floor space and was driven by a 1200 hp tandem compound engine with a 32 ft (9.8 m) flywheel with 28 ropes operated at 50rpm.