Latvian language (Latvian: latviešu valoda Latvian pronunciation: [ˈlatviɛʃu ˈvalɔda]), also known as Lettish, is an Eastern Baltic language belonging to the Baltic branch of the Indo-European language family, spoken in the Baltic region. It is the language of Latvians and the official language of Latvia as well as one of the official languages of the European Union. There are about 1.2 million native Latvian speakers in Latvia and 100,000 abroad. Altogether, 2 million, or 80% of the population of Latvia, spoke Latvian in the 2000s, before the total number of inhabitants of Latvia slipped to less than 1.9 million in 2022. Of those, around 1.16 million or 62% of Latvia's population used it as their primary language at home, though excluding the Latgale region it is spoken as a native language in villages and towns by over 90% of the population.

As a Baltic language, Latvian is most closely related to neighboring Lithuanian (as well as Old Prussian, an extinct Baltic language); however, Latvian has followed a more rapid development. In addition, there is some disagreement whether Latgalian and Kursenieki, which are mutually intelligible with Latvian, should be considered varieties or separate languages.

Latvian first appeared in print in the mid-16th century with the reproduction of the Lord's Prayer in Latvian in Sebastian Münster's Cosmographia universalis (1544), in Latin script.