William II (29 April 1469 – 11 July 1509) was Landgrave of Lower Hesse from 1493 and Landgrave of Upper Hesse after the death of his cousin, William III, Landgrave of Upper Hesse in 1500.

This immediately sparked the War of the Katzenelnbogen Succession, in which William sought to enforce his claim on the County of Katzenelnbogen with military might.

She died on 21 May 1500 after the marriage produced one child, William (27 March 1500 – 8 April 1500).

The same year on 20 October, his second marriage was to Anna of Mecklenburg-Schwerin (14 September 1485 – 12 May 1525), who bore him three children: In 1500, William II reunited the Landgraviate of Hesse after the death of his cousin William III.

In 1503, Emperor Maximilian I commissioned William with executing the ban on Elector Philip of the Palatinate.