The Sless or Slass is a Sanhaja Berber tribe settled on the banks of the Ouergha River in the Taounate Province. This tribe exists between two other Sanhaja tribes: the Feshtala tribe and the Mezraoua tribe.
The tribe was originally in the High Atlas before moving to the banks of the Ouergha River in the Almoravid era. They were part of the Hanjafa tribe with the Feshtala tribe, the Mezraoua tribe and other tribes.
- El Mekkaoui, Ahmed (2010). "Sless". In Toufiq, Ahmed (ed.). Ma'lamat al-Maghrib (Encyclopedia of Morocco). Vol. 25. al-Jamī‘a al-Maghribiyya li-l-Ta’līf wa-l-Tarjama wa-l-Nashr. p. 153.