Hunsrik (natively Hunsrik [ˈhunsɾɪk], Hunsrückisch or Hunsrickisch and Portuguese hunsriqueano or hunsriqueano riograndense), also called Riograndese Hunsrik, Riograndenser Hunsrückisch or Katharinensisch, is a Moselle Franconian language derived primarily from the Hunsrückisch dialect of West Central German which is spoken in parts of South America. A co-official language in the Brazilian municipalities of Antônio Carlos, Santa Maria do Herval, and São João do Oeste, Hunsrik is spoken in the states of Rio Grande do Sul, Santa Catarina, and Paraná, as well as some regions of neighboring Paraguay and Argentina. It has been an integral part of the historical and cultural heritage of the Brazilian state of Rio Grande do Sul since 2012, and considered an intangible cultural heritage of Santa Catarina state since 2016.

Hunsrik developed from the Hunsrückisch dialect spoken by immigrants from the Hunsrück region of Germany (Rhineland-Palatinate, Saarland) who settled in Brazil's southern region such as Rio Grande do Sul, beginning under the Empire of Brazil in 1824. This immigration later fell under the control of individual states, and then of private European investment enterprises. While primarily based on the Hunsrückisch branch of the German language, it has also been greatly influenced by other German dialects such as East Pomeranian and Plautdietsch and by Portuguese, the national language of Brazil. It has been influenced to a lesser extent by indigenous languages such as Kaingang and Guarani and by immigrant languages such as Italian and Talian.

Portuguese expressions and words are commonly imported into Hunsrik, particularly in reference to fauna and flora (which are different from those of Germany) and to technological innovations that did not exist when the original immigrants came to Brazil, leading to words like Aviong for airplane (Portuguese avião) instead of Flugzeug, Kamiong (Pt. caminhão, truck) instead of Lastwagen, Tëlevisong (Pt. televisão) instead of Fernseher, etc. Daily expressions are often calques (literal translations) of Portuguese.

Also common are the use of German suffixes attached to Portuguese words, such as Canecache, "little mug", from Portuguese caneca, "mug", and German diminutive suffix -chen (-che in Hunsrik); hybrid forms such as Schuhloja, "shoe shop", from German Schuh and Portuguese loja, and Germanized forms of Portuguese verbs: lembreere, "to remember"; namoreere "to flirt"; respondeere, "to answer" (Portuguese lembrar, namorar, and responder). However, regardless of these borrowings, its grammar and vocabulary are still largely Germanic.

Although Hunsrik is the most common Germanic language in south Brazil, the use of this language—particularly in the last three to four generations—continues to decrease. Glottolog classifies the language as "shifting" on its Agglomerated Endangerment Status.

The Hunsrückisch dialect, from which Hunsrik derived, has its origins in the Moselle Franconian dialects spoken in the Hunsrück region, on the banks of the Rhine and Moselle rivers, in western Germany. Germany, as a national state, only unified in 1871, so the standard German existing today was, until the 19th century, a literary language, the one used by Martin Luther in his famous translation of the Bible. The German people, in their daily lives, did not use standard German to communicate, but several regional dialects.

Until around 1800, Standard German was primarily a written language in Germany. Standard German was often learned as a foreign language and had an uncertain pronunciation. With the country's unification process and the mass literacy of the population, standard German has become the language used by speakers of different dialects to understand each other, although regional dialects have remained the language used at home.

With German immigration to Brazil, over the past two centuries, German dialects have also come to establish themselves as a regional language. However, something curious happened: while in Germany standard German served for speakers of different dialects to communicate, in Brazil, due to the still incipient consolidation of standard German when immigration started, this role was played by the Hunsrückisch dialect. There are two hypotheses for this phenomenon. The first because most immigrants would have come from Hunsrück, so their dialect predominated. The second because Hunsrückisch has intermediate features between the different German dialects, so it served as a koiné between speakers of various dialects. What is known is that German immigrants in Brazil came from different parts of Germany, so Hunsrik-speaking Brazilians do not necessarily descend from people from Hunsrück. In these German communities, the Hunsrückisch dialect remained the main language of communication for several decades. German colonies in the South were usually formed in regions of forest depopulated or inhabited by Indians, who were expelled for the arrival of immigrants. Due to this isolation, the Germans managed to create a "linguistic island", in which German was the main language, and not Portuguese. At the beginning of the 20th century, there were hundreds of thousands of second- and third-generation German-Brazilians who could barely speak Portuguese. This differentiation favored the feeling of a minority group, which allied itself with the formation of solid ethnic institutions, such as schools, churches, social associations and a German-language press. All of these elements combined promoted a general feeling of "cultural group".