Finnish Sign Language is the sign language most commonly used in Finland. There are 5000 (estimate) Finnish Deaf who have Finnish Sign Language as a mother tongue. Linguistically Finnish Sign Language is closest to Swedish Sign Language, from which it began to separate as an independent language in the middle of 19th century.

Finnish legislation recognized Finnish Sign Language as one of Finland's domestic languages in 1995 when it was included in the renewed constitution. Finland then became the third country in the world to recognize sign language as a natural language and the right to use it as a mother tongue.