Longobardia (Greek: Λογγοβαρδία, also variously Λογγιβαρδία, Longibardia and Λαγουβαρδία, Lagoubardia) was a Byzantine term for the territories controlled by the Lombards in the Italian Peninsula.

In the ninth and tenth centuries, it was also the name of a Byzantine military-civilian province (or thema) known as the Theme of Longobardia located in southeastern Italy.

[1][2] In its strictest and most technical sense, the name referred to the province (thema) which encompassed the modern Italian region of Apulia and parts of Basilicata, with Bari as its capital.

[6] The campaigns of Nikephoros Phokas the Elder in the mid-880s and of his successors greatly expanded the area under Byzantine control, which came to include all of Calabria, Apulia, and the Basilicata.

[2][3] The Varangian Guard fought as part of the Byzantine army in several campaigns in the area, known to them as Langbardland; in their Scandinavian homeland, their exploits are commemorated in the Italy runestones.