John II, Count of Nassau-Dillenburg (c. 1365-May 1443 at Dillenburg) was Count of Nassau-Dillenburg in Siegen and Dillenburg and son of Count John I, Count of Nassau-Dillenburg and Margareta of the Marck.
After the death of Count John I in 1416 his lands were not divided, but instead overseen by all four of his surviving sons Adolf, John II, Engelbert I and John III. John II had led a military life, and he never married.
Apparently he was Archbishop of Mainz from 1396-1419.