The wilaya of Tissemsilt is a wilaya of Algeria (in Berber: ⴰⴳⴻⵣⴷⵓ ⵏ ⵜⵉⵙⵎⵙⵉⵍⵜ; in Arabic: ولاية تيسمسيلت), located in the west of the country.

The wilaya is located in the west of the country in the high plateau region, 220 km from Algiers and 275 km from Oran. It is bordered:

 to the north, by the wilayas of Wilaya de Aïn Defla;

to the west, by the Wilaya of Relizane and Wilaya of Chlef;

to the east, by the wilaya of Médéa;

to the south, by the wilaya of Tiaret.et Wilaya of Djelfa.

relief:

The territory of the wilaya is made up of mountainous areas which represent 65% of its overall surface, the rest is occupied by the highlands and to a lesser extent the steppes3.

 The wilaya is home to Theniet El-Haâd National Park, known for its cedar forest, the forest area covers 20% of the territory of the wilaya4.

Weather 

The wilaya is characterized by a dry continental climate that is cold in winter and hot in summer. It is semi-arid in the South and the Center and Sub-humid in the Ouarsenis massif. The rainfall varies between 400 and 500 mm/year and the temperature between 8 and 30°C.

Water resources

The wilaya includes the following dams:

Koudiet Errosfa Dam

Bougara Dam

Mghila Dam

Tamellaht Dam

Dam of Oued Aïssa

These dams are part of the 65 operational dams in Algeria1 while 30 others are under construction in 2015 

demography:

In 2008, the population of the wilaya of Tissemsilt was 294,476 inhabitants against 227,542 in 1987. 6 municipalities then exceeded the bar of 20,000 inhabitants in 2008