Aleksandra Kornhauser Frazer (26 September 1926 - 17 May 2020) was a Slovenian chemist and environmentalist. She was a Professor of Chemistry at the Faculty of Natural Sciences and Engineering and Director at the International Centre for Chemical Studies, of the University of Ljubljana, Slovenia. In 1988, she was elected as a member of Academia Europaea.
She was professionally active until the age of 90, when she ended her term as the dean of Jožef Stefan International Postgraduate School. She received the Zois Prize for life-time achievements in 1997, the highest prize in the scientific field in Slovenia. She was also an honorary citizen of Ljubljana.
She died in Ljubljana on 17 May 2020 at the age of 93.