Livonian (Livonian: līvõ kēļ or rāndakēļ) is a Finnic language that originated on the Livonian Coast of the Gulf of Riga, located in the north of the Kurzeme peninsula in Latvia but also used to be spoken in the Salaca River valley. Although its last known native speaker died in 2013, a child, Kuldi Medne, born in 2020, is reported to be a native speaker of Livonian. Her parents are Livonian language revival activists Jānis Mednis and Renāte Medne. Also, there are about 40 reported L2 speakers and 210 having reported some knowledge of the language. Possibly uniquely among the Uralic languages but similarly to Latvian and Lithuanian, Livonian has been described as a pitch-accent language (or restricted tone language, see below).

Some ethnic Livonians are learning or have learned Livonian in an attempt to revive it, but because ethnic Livonians are a small minority, opportunities to use Livonian are limited. The Estonian newspaper Eesti Päevaleht erroneously announced that Viktors Bertholds, who died on 28 February 2009, was the last native speaker who started Latvian-language school as a monolingual. Some other Livonians had argued, however, that there were some native speakers left, including Viktors Bertholds' cousin, Grizelda Kristiņa, who died in 2013. An article published by the Foundation for Endangered Languages in 2007 stated that there were only 182 registered Livonians and a mere six native speakers. In a 2009 conference proceeding, it was mentioned that there could be "at best 10 living native" speakers of the language.

The promotion of the Livonian language as a living language has been advanced mostly by the Livonian Cultural Centre (Līvõ Kultūr Sidām), an organisation of mostly young Livonians. Livonian as a lesser used language in Latvia – along with Latgalian – is represented by the Latvian Bureau of Lesser Used Languages (LatBLUL), formerly a national branch of the European Bureau of Lesser Used Languages (EBLUL).

The language is taught in universities in Latvia, Estonia, Finland and Sweden, which constantly increases the pool of people with some knowledge of the language who do not permanently reside in Latvia.

In the 19th century, about 2,000 people still spoke Livonian; in 1852, the number of Livonians was 2,394. Various historical events have led to the near total language death of Livonian:

In the 13th century, the native Livonians inhabited all the areas around the Gulf of Riga, except for the Estonian island of Saaremaa. In the 12th–13th centuries the Livonian lands were conquered by the Teutonic Order. The conquest led to a strong decrease in the number of speakers of the Livonian language, empty Livonian lands inhabited by the Latvians, which contributed to the replacement of the Livonian language in favor of Latvian. It is estimated that at the time of the German colonization, there were 30,000 Livonians. In the 19th century the number of speakers of the Couronian dialect is estimated as follows: 2,074 people in 1835, 2,324 people in 1852, 2,390 people in 1858, 2,929 people in 1888. According to the Soviet Census of 1989, 226 people were Livonian, and almost half of them spoke Livonian. According to estimates of the Liv Culture Center in 2010, only 40 people spoke Livonian in everyday life. In 2013, there was no one who spoke Livonian in everyday life.

The first Livonian words were recorded in the Livonian Chronicle of Henry. The first written sources about Livonian appeared in the 16th century. The collection of Livonian poems "Mariners sacred songs and prayers" (Latvian: Jūrnieku svētās dziesmas un lūgšanas) was translated into Latvian by Jānis Prints and his son Jānis Jr. and was published in 1845. The first book in Livonian was the Gospel of Matthew, published in 1863 in London in both the eastern and western Courland dialects. It was translated into eastern Curonian by Nick Pollmann and into western Curonian by Jānis Prints and Peteris. The plan with the book was to establish a standard orthography by F. Wiedemann, which consisted of 36 letters with many diacritics. The total circulation was 250 copies. The Livonians received only one copy of each dialect. The second book in Livonian was the same Gospel of Matthew, published in 1880 in St. Petersburg, with an orthography based on Latvian and German.

In the interwar period, there were several dozen books published in Livonian, mainly with the help of Finnish and Estonian organizations. In 1930, the first newspaper in Livonian, "Līvli", was published. In 1942, a translation of the New Testament was published in Helsinki. It was translated by Kōrli Stalte, with help from the Finnish linguist Lauri Kettunen. After WWII, books in Livonian were no longer published, as Latvia was occupied by the Soviet Union. The whole area of the Livonian Coast became a restricted border zone under tight Soviet supervision. Coastal fishing was gradually eliminated in the smaller villages and concentrated in the larger population centres of Kolka, Roja, and Ventspils. Limits were placed on freedom of movement for inhabitants. All of these factors contributed to the decline of the language, although some initiatives appeared from the early 1970s onwards.