[3] Born in Vienna, Kneissl spent part of her childhood in Amman, where her father worked as a pilot for King Hussein of Jordan and also was involved in developing Royal Jordanian Airlines.

From 1990 to 1998 she worked in the cabinet of ÖVP foreign minister Alois Mock, in the International Law Office, and was posted abroad in Paris and Madrid.

[4] In July 2016, after the Brexit referendum, she criticized European Commission president Jean-Claude Juncker as "cynic of power", "rowdy" and "arrogant", who "behaves as a Brussels Caesar, who has made it his goal to break agreements, if it seems useful.

She criticized Zionism, founded by Austro-Hungarian publicist Theodor Herzl, as a "blood and soil ideology" based on German nationalism in the 19th century.

In September 2015, she said on public television that one of the reasons for the revolts in the Arab world was "these many young men", "testosterone-controlled", "who no longer managed to get a wife today" because they have neither work nor their own home, and thus could not achieve "status as a man in a traditional society".

[4] She also sharply criticized German Chancellor Angela Merkel as "grossly negligent" for her selfies with refugees, and later described the EU-Turkey statement, 18 March 2016[12] as "nonsense".

[4] Such remarks led to criticism and caused doubts concerning her self-definition as a "conservative free-thinker", but also gained praise and sympathy from populist anti-migration party FPÖ, to whose events she was increasingly invited.

[4] Kneissl was praised by FPÖ leader Heinz-Christian Strache as "a great personality, a female Kreisky perhaps in the future when it comes to mediation, acceptance and advertising for Austria abroad.

Pictures of this gesture were widely published in Russian and international media, and sparked major outrage and criticism due to her perceived naivety.

[2] In March 2021, Kneissl, who had disclosed financial problems at the beginning of the COVID-19 pandemic,[16] was reported to have been appointed by the Russian Government to the Board of Directors of the state gas company Rosneft.