Délvidék (Hungarian for "southern land" or "southern territories") is a historical political term referring to varying areas in the southern part of the Pannonian Plain, which was administered by the Kingdom of Hungary (part of Austria-Hungary) before 1918. Today, these areas are divided between Croatia (northern part), Serbia (mainly Vojvodina region), Romania (Banat), Slovenia (Prekmurje) and Hungary (Baranya, Bácska and Bánát).
In the Middle Ages, like the names Alvidék ("lower land") and Végvidék ("borderland"), Délvidék might refer to several counties of the Kingdom of Hungary (Verovitiensis, Poseganus, Sirmiensis, Bacsensis, Torontaliensis, Temesiensis, Keve) and vassal banates (Machoviensis, Usora, Soli, Severin) beyond the Danube and the Sava.
By the 18th and 19th centuries, Délvidék referred only to Batschka (Bácska, Bačka) and Banat. After the 1918 dismemberment of Austria-Hungary, the meaning was further narrowed to only those areas of the pre-war Kingdom of Hungary assigned to the new Yugoslav state. In the Second World War, the Yugoslav areas occupied by Hungary (Bačka, Baranja, Međimurje, and Prekmurje) were in some Hungarian sources called "az anyaországhoz visszatért délvidéki területnek" ("the southern land returned to the motherland"). Banat, which remained part of German-occupied Serbia and was ruled by its German minority, was no longer considered part of the concept.
In contemporary usage, Délvidék might have several uses. It can refer to the imprecisely defined area of Serbia's northern Pannonian Basin including Vojvodina, the Belgrade region, and the Mačva plain as well as eastern Croatia (Baranja, western Syrmia and Slavonia). Sometimes the term might be used (especially by irredentist) in the narrow sense of Vojvodina (or some Hungarian-populated parts of Vojvodina) although it has largely been replaced by Vajdaság, the Hungarian name for Vojvodina. "Délvidék Hungarians" (délvidéki magyarok) can refer to Hungarians in Vojvodina or, in a larger sense, to both the Vojvodina Hungarians and Hungarians of Croatia.