Seeland (Dan. Sjoelland), an island of Denmark, bounded N. by the Cattegat, separated E. by the Sound from Sweden, S. by the Baltic from the islands of Möen, Falster, and Laa-land, and W. by the Great Belt and its continuations from Langeland, Fünen, and Samsö; length 81 m., greatest breadth 66 m.; area, 2,721 sq.m.; pop. in 1870, 560,510. It is irregular in shape and much indented by arms of the Baltic, and in the north an arm of the Cattegat extends far into the interior. The surface is generally flat. The soil is an extremely fertile alluvium resting on beds of mussel shells and corallines. The chief product is grain. Extensive forests once covered the island, but timber is now scarce. The climate is humid and milder than in other places in the same latitude. Frederiksborg, the new part of the city of Copenhagen, stands on this island, which together with Möen and Samsö forms one of the main divisions of Denmark.