Lower Austria South (German: Niederösterreich Süd), also known as Electoral District 3E (German: Wahlkreis 3E), 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.

[6] Electoral regulations require the allocation of seats amongst the electoral districts to be recalculated following each national census and in June 2013 the number of seats allocated to Lower Austria South was increased to five based on the population as at the 2011 national census.

[7] The number of seats allocated to Lower Austria South was reduced to four in June 2023 based on the population as at the 2021 national census.

[8] Lower Austria South currently elects four of the 183 members of the National Council using the open party-list proportional representation electoral system.

[13][14] Electors may cast one preferential vote for individual candidates at the regional, state and federal levels.