Russian linguist, archaeologist, and ethnographer specializing in the languages of the Caucasus.

A professor at St. Petersburg University from 1900, Marr published numerous collections of old Georgian and Armenian literature and attempted to prove a relationship between the Caucasian and Semitic-Hamitic and Basque languages. Marr took his ideas further in 1924, proposing a monogenetic theory of language: all languages evolved from one original made up of four basic elements (sal, ber, yon, rosh). Each language of the world had attained its own stage of evolution. Languages themselves were the products of the underlying socioeconomic structure and were therefore class-related and not national phenomena. Marr's ideas lent themselves to Marxist theory; and became the “official” linguistic approach until 1950, when Stalin denounced it. After his death in 1934, Marr's ideas were adopted and expanded by the Institute of Language and Thought.

Marr's discredited theory has obscured his legitimate accomplishment: exciting interest in the many non-Indo–European languages within republics of the former Soviet Union.