Xanthi (pronounced [ˈksanθi], Greek: Περιφερειακή ενότητα Ξάνθης) is one of the regional units of Greece.

Xanthi borders the Bulgarian provinces of Smolyan and Kardzhali to the north, and the Aegean Sea to the south.

The regional unit of Kavala lies to the west, Drama to the northwest and Rhodope to the east.

The Rhodope Mountains cover the northern part of the regional unit.

The manors of the old city Xanthi, many of which are still intact, testify to the prosperity of the tobacco merchants during this period.