In the late 1830s, William IV of the United Kingdom wished to marry Alexander to his niece Princess Alexandrina Victoria of Kent (and future Queen of the United Kingdom).
Nothing came of this however, as Victoria remarked to her uncle Leopold I of Belgium, "The Netherlander boys are very plain and have a mixture of Kalmuck (Mongol) and Dutch in their faces, moreover they look heavy, dull, and frightened and are not at all prepossessing.
So much for the Oranges, dear Uncle".

It was suggested in 1840 that Alexander should eventually marry Isabella II of Spain when she came of age, allowing him to become regent.
 However, opposition from other crowns and King William’s objection to her religion (she was Catholic) prevented any marriage between the two.
Alexander never married, as Princess Sophie wrote to Lady Malet on May 4, 1847, "but I am in pleasant company with Prince Alexander[...]It is not that he courts me, for he does not yet know what a woman is, but he gives me all friendship he is able to give."
He had no issue.
In the late 1830s, William IV of the United Kingdom wished to marry Alexander to his niece Princess Alexandrina Victoria of Kent (and future Queen of the United Kingdom). Nothing came of this however, as Victoria remarked to her uncle Leopold I of Belgium, "The Netherlander boys are very plain and have a mixture of Kalmuck (Mongol) and Dutch in their faces, moreover they look heavy, dull, and frightened and are not at all prepossessing. So much for the Oranges, dear Uncle".
It was suggested in 1840 that Alexander should eventually marry Isabella II of Spain when she came of age, allowing him to become regent.  However, opposition from other crowns and King William’s objection to her religion (she was Catholic) prevented any marriage between the two. Alexander never married, as Princess Sophie wrote to Lady Malet on May 4, 1847, "but I am in pleasant company with Prince Alexander[...]It is not that he courts me, for he does not yet know what a woman is, but he gives me all friendship he is able to give." He had no issue.
Prince Alexander of the Netherlands