Samuil (Bulgarian: Самуил [sɐmuˈiɫ]; Turkish: Işıklar) is a village in northeastern Bulgaria, part of Razgrad Province, located in the geographic region of Ludogorie.

It is the administrative centre of the homonymous Samuil Municipality, which lies in the southeastern part of the Province.

The area was inhabited by the Getae and the Romans in Antiquity and by the Slavs and Bulgars in the Middle Ages.

The construction of Baron Hirsch's Rousse-Kaspichan-Varna railway line in 1867-1868 turned the small village of Ishiklar into a railway station of local importance, with the first settlers being Greek merchants and harvesters.

Samuil municipality covers an area of 250 square kilometres and includes the following 14 places: Ethnic Turks constitute 75% of the population, Bulgarians being 14% and Roma 11%.