Farnworth is a town and an unparished area within the Metropolitan Borough of Bolton in Greater Manchester, England. It is located 2.3 miles (3.7 km) southeast of Bolton, 5 miles south-west of Bury (7 km), and 9 miles (14.5 km) northwest of Manchester.Historically in Lancashire, Farnworth lies on the River Irwell and the River Croal, and, according to the United Kingdom Census 2001, it has a population of 25,264 people.