Laoighis, Laois, or Leix , county (1991 pop. 52,325), 664 sq mi (1,720 sq km), central Republic of Ireland. The county seat is Port Laoise (Maryborough). A part of the central plain of Ireland, Laoighis is generally level, except for the Slieve Bloom Mts. in the northwest, which is the site of several forestry plantations. The Barrow and the Nore are the chief rivers. Agriculture (wheat, barley, and sugar beets) and dairy farming are the main occupations. Industries include woolens, woodworking, and pharmaceuticals.