Carpathian Ruthenia (Rusyn: Карпатьска Русь Karpat'ska Rus'; Ukrainian: Закарпаття Zakarpattia; Slovak and Czech: Podkarpatská Rus; Polish: Zakarpacie; Hungarian: Kárpátalja;) is a historic region on the border between Central and Eastern Europe, mostly located in western Ukraine's Zakarpattia Oblast, with smaller parts in easternmost Slovakia (largely in Prešov Region and Košice Region) and the Lemko Region in Poland.

During the Middle Ages the region was part of Kievan Rus'. From the Hungarian conquest of the Carpathian Basin to World War I most of this region was part of the Kingdom of Hungary. In the interwar period, it was part of the First and Second Czechoslovak Republic. During World War II, the region was annexed by the Kingdom of Hungary once again. After the war, it was annexed by the USSR and became part of Soviet Ukraine.

It is an ethnically-diverse region, inhabited mostly by people who regard themselves as ethnic Ukrainians, Rusyns, Lemkos, Boykos, Hutsuls, Hungarians, Romanians, Slovaks and Poles. It also has small Jewish and Romani minorities. The most commonly-spoken languages are Rusyn, Ukrainian, Hungarian, Romanian, Slovak, and Polish.