The Surname Law of the Republic of Turkey was adopted on June 21, 1934. The law required all citizens of Turkey to adopt the use of hereditary, fixed, surnames. Much of the population, particularly in the cities as well as Turkey's Christian and Jewish citizens, already had surnames, and all families had names by which they were known locally. The Surname Law of 1934 enforced not only the use of official surnames but also stipulated that citizens choose Turkish language names. The law appointed the male head of household as the person who would choose the surname, but there was a lot of variety as to how names were taken or chosen.

Surname law can refer to any law regulating the use of surnames.