LEITRIM (County of): a county, of which a very small portion is maritime, in the province of CONNAUGHT, bounded on the west by the counties of Sligo and Roscommon, on the south by that of Longford, on the east by those of Cavan and Fermanagh, and on the north by that of Donegal and by Donegal bay. It extends from 53° 45' to 54° 29' (N. Lat.) and from 7° 33' to 8° 8' (W. Lon.); and comprises, according to the Ordnance survey, 420,375 statute acres, of which 266,640 are cultivated land, 128,167 are unimproved mountain and bog, and 25,568 are under water. The population, in 1821, was 124,785, and in 1831, 141,303.