Bacup /ˈbeɪkʌp/ is a town within the Rossendale borough of Lancashire, England. It is located in the South Pennines, along Lancashire's eastern boundary with West Yorkshire. The town sits within a rural setting in the Forest of Rossendale in the steep-sided upper-Irwell Valley, through which the River Irwell passes. It is 3.5 miles (5.6 km) east of Rawtenstall, 6.4 miles (10.3 km) north of Rochdale, and 21 miles (34 km) east of Preston.