Baron Zsigmond Forgách de Ghymes et Gács, sometimes Sigismund Forgách (Slovak: Žigmund Forgáč; 1559 – 23 June 1621, in Nagyszombat, today Trnava in Slovakia), was a Hungarian nobleman in the Kingdom of Hungary, who served as Palatine from 11 May 1618 to 23 June 1621.

In 1605 at Kassa (today: Košice, Slovakia), he negotiated unsuccessfully, along with György Thurzó and Benedek Pogrányi, with the envoys of Bocskay.

He was appointed one of the royal commissioners for repossession of the lands which returned to the Crown in 1607, according to the Treaty of Vienna between Bocskay and Archduke Matthias.

After the death of György Thurzó, following a two-year period of vacancy, he was elected Palatine by the Diet of Hungary.

He rebuilt the castle of Gács (today: Halič, Slovakia) on land which had been part of the estate of the owner of the county since 1598, choosing a site that was both strategic and offering natural fortifications.

Wings of this hexagon led into a courtyard with plain walls, later covered with many murals depicting figures of the Roman emperors and the Hungarian kings between its windows and entrances.