Thermenregion, also known as Electoral District 3F (German: Wahlkreis 3F), is one of the 39 multi-member regional electoral districts of the National Council, the lower house of the Austrian Parliament, the national legislature of Austria.

Thermenregion was established in 2016 from parts of Greater Vienna and Lower Austria South East following the re-organisation of the regional electoral districts in Lower Austria to reflect the new administrative district structure.

[6] Electoral regulations require the allocation of seats amongst the electoral districts to be recalculated following each national census and in June 2023 the number of seats allocated to Thermenregion was increased to six based on the population as at the 2021 national census.

[7] Thermenregion currently elects six of the 183 members of the National Council using the open party-list proportional representation electoral system.

[12][13] Electors may cast one preferential vote for individual candidates at the regional, state and federal levels.