Willem II (1792–1849) was King of the Netherlands from 1840 to 1849.
He was born at The Hague on 6 December 1792. Educated in exile, he returned in 1813 with his father, Willem I, who had become King of the United Netherlands in 1813. Popular in the southern Netherlands (Belgium), Willem II might have been able to prevent the separation of Belgium from the United Netherlands if his father had not interfered. Crowned King after his father's abdication in 1840, Willem II faced internal political problems which, in 1848, resulted in a liberal constitution, greatly curtailing the power of the Crown. He died on 17 March 1849.