Sălaj (Romanian pronunciation: [səˈlaʒ]) (also known as Land of Silvania, silva, -ae means "forest") is a county (județ) of Romania, located in the north-west of the country, in the historical regions of Crișana and Transylvania. It is bordered to the north by Satu Mare and Maramureș counties, to the west and south-west by Bihor County, and to the south-east by Cluj County. Zalău is the county seat as well as its largest city.
In Hungarian, it is known as Szilágy megye, in Slovak as Salašská župa, and in German as Kreis Zillenmarkt. The county is named after the Sălaj River, which gets its name from Hungarian Szilágy "elm creek", composed from szil, "elm" and ágy "riverbed".
On 28 July 1978, a team of speleologists discovered in the cave of Cuciulat Paleolithic paintings about 12,000 years old, unique in Romania. Nicknamed the "Altamira of Romania", the cave features several red paintings of animals, including horses and felines. These are the first manifestations of this kind known in Southeastern Europe.