多尔县（Door County, Wisconsin）是位于美国威斯康辛州东北部的一个县，西临绿湾，东临密西根湖。面积6,138平方公里 （其中4,888平方公里，即79.63%的面积为水面面积）。根据美国2000年人口普查估计，共有人口27,961人。县治斯特金贝 (Sturgeon Bay)。

成立于1851年2月11日，县政府成立于1861年。县名来自多尔半岛和华盛顿岛之间的水道：由于当地多船难，法国人称之为「死门」 （Porte de Morte）。

Door County is a county in the U.S. state of Wisconsin. As of the 2010 census, the population was 27,785. Its county seat is Sturgeon Bay.

The county was created in 1851 and organized in 1861. It is named after the strait between the Door Peninsula and Washington Island. The dangerous passage, which is now scattered with shipwrecks, was known to early French explorers and local Native Americans. Because of the natural hazards of the strait, where the waters of Green Bay meet the open body of Lake Michigan, they gave it the French appellation Porte des Morts, which in English means "Death's Door."