Jan II the Mad, Duke of Żagań (1439-1449 and 1461-1468 and again in 1472) (d. 1504)

Jan II the Mad also known as the Bad, the Wild or the Cruel (16 April 1435 – 22 September 1504), was a Duke of Żagań-Przewóz since 1439 (with his brothers as co-rulers until 1449), from 1449 Duke of Przewóz (as co-ruler of his younger brother), during 1461–1468 and briefly in 1472 Duke of Żagań and during 1476–1488 Duke of half-Głogów (the Duchy was finally reunited in 1480).

He was the fourth and youngest son of Duke Jan I of Żagań by his wife Scholastika, daughter of Rudolf III, Duke of Saxe-Wittenberg and Elector of Saxony.