Alexander, Prince of Orange (Willem Alexander Karel Hendrik Frederik; 25 August 1851 – 21 June 1884), was heir apparent to his father King William III of the Netherlands from 11 June 1879 until his death.

Alexander held the position of heir apparent until his own death, at age 32, on 21 June 1884 in The Hague from typhus.

He was buried in the new royal burial vault in the Nieuwe Kerk in Delft on 17 July 1884.

[3] After his death, his half-sister, the future Queen Wilhelmina, became heir presumptive to the Dutch throne.

[4] Alexander's death meant that on the death of William III the Grand Duchy of Luxembourg came into the hands of Duke Adolphus from the Walram line of the House of Nassau, as under the terms of the house-treaty a princess could not succeed to that title.