Ebba Ninna Back Carstensen (23 August 1885 – 13 October 1967) was a Danish painter.
From 1909 to 1913, she attended the Royal Danish Academy of Fine Arts, studying under Laurits Tuxen and Valdemar Irminger.
Thereafter her painting was increasingly influenced by modern trends she learned from Danish painters who had returned from Paris.
She abandoned Impressionism in favour of the more disciplined style of Cubism, evoking a "return to nature".
[3] Carstensen was a member of the Decembrister (Decemberists), a group formed by Svend Albrectsen, Søren Hjorth Nielsen, Holger J. Jensen, Erik Sievert and Jørgen Thomsen who were unhappy with the opportunities for exhibiting and arranged their own exhibition each year in December.