John Francis Desideratus (28 July 1627 – 17 December 1699) was count of Nassau-Siegen and stadtholder of Limburg and Upper Guelders.

He succeeded his father in 1638 as count of Nassau-Siegen, but had to cede a part of the County to the Protestant branch of the family in 1648.

Like his father, John Francis Desideratus was a general in Spanish service.

At his death he was succeeded by his eldest surviving son William Hyacinth.

They had three children: In Brussels on 9 February 1669 he married Baroness Isabella Clara du Puget de la Serre (1651 – 19 October 1714).