Estonian (eesti keel; pronounced [ˈeːsti ˈkeːl] ( listen)) is the official language of Estonia, spoken by about 1.1 million people in Estonia and tens of thousands in various émigré communities. It is a Uralic language and is closely related to Finnish.

One distinctive feature that has caused a great amount of interest among linguists is what is traditionally seen as three degrees of phoneme length: short, long, and "overlong", such that /toto/, /toˑto/ and /toːto/ are distinct. In actuality, the distinction is not purely in the phoneme length, and the underlying phonological mechanism is still disputed.^{[citation needed]}

Kas siis selle maa keel
Laulutuules ei või
Taevani tõustes üles
Igavikku omale otsida?
In English:
Cannot the language of this land
In the wind of incantation
Rising up to the heavens
Seek for eternity?

Those lines have been interpreted as a claim to reestablish the birthright of the Estonian language. Kristjan Jaak Peterson (1801–22), the first student at the then German-language University of Tartu to acknowledge his Estonian origin, is commonly regarded as a herald of Estonian national literature and considered the founder of modern Estonian poetry. His birthday on March 14 is celebrated in Estonia as the Mother Tongue Day.