LEIGH, a large parish, consisting of two chapelries and four townships, in the hundred of West Derby, in the county of Lancaster, 198 miles from London. It is placed conveniently for water communication with most of the great rivers of the kingdom; from which, and the great extension of the cotton trade, its population has been rapidly augmented. The inhabitants amounted in 1801 to 12,976, in 1811 to 15,565, in 1821 to 18,372, and in 1831 to 20,083.