It shares borders with Austria (Burgenland), Slovenia (Mura Statistical Region), and the Hungarian counties of Győr-Moson-Sopron, Veszprém, and Zala.

Vas is also the name of a historic administrative county (comitatus) of the Kingdom of Hungary.

In the Vendvidék in 1919 was founded an unrecognized state the Prekmurje Republic, similar to Burgenland the Lajtabánság.

The remainder stayed in Hungary, as the present Hungarian county Vas.

39,000 persons in Vas County did not declare their ethnic group at the 2011 census.