Horwich, an urban district in the Westhoughton parliamentary division of Lancashire, England, 4 m. W.N.W. of Bolton, on the Lancashire and Yorkshire railway. Pop. (1901) 15,084. It lies beneath the considerable elevation of Rivington Pike, where formerly was a great forest. It has extensive locomotive works, and there are large stone quarries in the district. Bleaching and cotton-spinning and the manufacture of fire-bricks and tiles are carried on.