Surduc (Hungarian: Szurduk; German: Surdecken; Yiddish: סורדוק) is a commune in Sălaj County, Transylvania, Romania. It is composed of seven villages: Brâglez, Cristolțel, Solona, Surduc, Teștioara, Tihău and Turbuța.

The name of the commune has its origin in the morphological configuration of the area (surduc means gorge, pass or narrow valley with sudden and steep slopes). Other sources claim that the name of the commune is of Slavic origin, surdec meaning meander; near Surduc, Someș River makes the biggest turn in its course. According to a local legend, between Bălan and Solona (the oldest villages in the area) there were no settlements but only an inn, in the place called Sub grădiște (Under the hillock), owned by a short and deaf man (in Romanian surd means deaf). The travelers nicknamed him "surduc", hence the name.

Southeast of Surduc, on a hill known as Grădiște or Cetate, a Roman fort was discovered on a plateau overlooking the expansive Someș Plain at its confluence with the Almaș River. The initial earth-and-timber phase of the fort was constructed in 106 AD by a vexillation of the Legio XIII Gemina. A later stone phase was built by the Cohors I Cananefatium. The site has not undergone systematic archaeological investigation, with only limited surveys conducted in 1958 and 1997. The corners of the fort are aligned with the cardinal directions. The porta praetoria was located on the northwest side, facing the Someș River. Due to the current state of research, the precise location of the vicus remains unknown.

Surduc is probably the successor of an older settlement, recorded as Sumbur in 1320. According to József Kádár [hu]'s Monograph of Szolnok-Doboka County, Surduc was first mentioned in 1554 as Naghzwrdok ("Great Surduc"), when Anna Somi, Imre Balassa's widow, bequeathed a quarter of the estate to her husband, Boldizsár Patócsi. The village originally belonged to the nobles of Csákigorbó (present-day Gârbou), being part of the domain of the Almaș Fortress [ro]. In the Middle Ages and pre-modern times it was part of the Szolnok-Doboka County and Inner Szolnok County [hu]. By 1696, Surduc appears as a village under Turkish occupation.

Between 1641 and 1810 the estate was owned by the Csáky family. By 1644 they had a noble curia here; only its servants' house is preserved to this day. In 1705 it hosted Prince Francis II Rákóczi, before the confrontation of his troops with the Habsburg Imperial Army led by Ludwig von Herbeville in Zsibó (present-day Jibou). The curia was probably transformed into a castle in the 18th century, because at the beginning of the 19th century it was already recorded as a castle.

In 1810 the village became the property of the Jósika family of Branyicska. The best known owner is the novelist Miklós Jósika (1794–1865), nicknamed "Hungarian Walter Scott", who settles here after his first wife's divorce. He revitalizes the area, building a series of agricultural buildings, a chapel and probably establishing the current form of the castle. A family property inventory from 1854 records a 17-room building, including the novelist's office and a chapel. The castle and the village were almost completely destroyed in December 1848, during the Hungarian Revolution of 1848, when the Austrians under Captain Binder occupied the village with thousands of insurgents. As the leader of the Hungarian liberal nobility, Jósika was the first landowner in Doboka County to free the serfs from the Surduc estate and their villages on 23 April 1848, two months before the Hungarian Diet. János, the final landowner of the Jósika family's Surduc estate and prefect of Sălaj County following the Vienna Dictate, was expropriated on 28 May 1945. The communist regime turned the castle into a tractor repair station, and after 1991 it was bought by Agromec. Currently, the castle is overgrown with vegetation, in an advanced state of degradation.

With an area of 71.42 km² (6th among the county communes), Surduc occupies a central-eastern position within Sălaj County, at the contact of four important relief units: Someș Corridor, Șimișna–Gârbou Hills, Almaș–Agrij Depression and Prisnel Peak. The commune is located to the east of the "intracarpathian yoke" (Meseș Mountains–Dumbrava Hill–Prisnel Peak). The Șimișna–Gârbou Hills that make up most of the commune are represented only by their northern termination, which gradually inclines in this direction towards the wide terraced corridor of the Someș, to which the Almaș–Agrij Depression also opens. The corridor is limited to the west by the last extensions of the Prisnel Peak, represented by the Rona Peak (438 m).

The relief is very varied, formed by an association of hilly peaks and valleys between slopes, all resulting from the fragmentation of the northwestern part of the Someș Plateau. In terms of altitude, the relief is between about 200 m in the meadows of Someș and its tributaries and 607 m in Pietrosu Peak, in the southeastern part of the commune.