Slavonic-Serbian (славяносербскій, slavyanoserbski), Slavo-Serbian, or Slaveno-Serbian (славено-сербскiй, slaveno-serbski; Serbian: славеносрпски/slavenosrpski) was a literary language used by the Serbs in the Habsburg Empire, mostly in what is now Vojvodina, from the mid-18th century to the first decades of the 19th century. It was a linguistic blend of Church Slavonic of the Russian recension, vernacular Serbian (Štokavian dialect), and Russian.
At the beginning of the 18th century, the literary language of the Serbs was the Serbian recension of Church Slavonic (also called Serbo-Slavonic), with centuries-old tradition. After the Great Serb Migration of 1690, many Serbs left Ottoman-held territories and settled in southern areas of the Kingdom of Hungary in the Habsburg Empire, mostly in what is now Vojvodina. The Serbian Orthodox Church in these areas was in need of liturgical books, and the Serbian schools were in need of textbooks. The Habsburg court, however, did not allow the Serbs to establish their printing presses. The Serbian Church and schools received ample help in books and teachers from the Russian Empire. By the mid-18th century, Serbo-Slavonic had been mostly replaced with Russo-Slavonic (Russian recension of Church Slavonic) as the principal literary language of the Serbs.
Around that time, laymen became more numerous and notable than monks and priests among active Serbian writers. The secular writers wanted their works to be closer to the general Serbian readership, but at the same time, most of them regarded Church Slavonic as more prestigious and elevated than the popular Serbian language. Church Slavonic was also identified with the Proto-Slavic language, and its use in literature was seen as the continuation of an ancient tradition. The writers began blending Russo-Slavonic, vernacular Serbian, and Russian, and the resulting mixed language is called Slavonic-Serbian. The first printed work in Slavonic-Serbian appeared in 1768, written by Zaharije Orfelin. Before that, a German–Slavonic-Serbian dictionary was composed in the 1730s. The blended language became dominant in secular Serbian literature and publications during the 1780s and 1790s. At the beginning of the 19th century, it was severely attacked by Vuk Karadžić and his followers, whose reformatory efforts formed modern literary Serbian based on the popular language. The last notable work in Slavonic-Serbian was published in 1825.