Ada Konstantia Nilsson (September 21, 1872 – May 23, 1964) was an early Swedish woman medical doctor.

Her father, who helped to run the textile workers cottage industry, died when she was thirteen and she went to live in Stockholm.

[3] The magazine Tidevarvet was founded in 1923[4][5] by Kerstin Hesselgren, educator Honorine Hermelin, Ada Nilsson, Elisabeth Tamm, a liberal politician, and Elin Wägner, an author.

Nilsson was one of the principal funders of the project and became editor-in-chief with her new friend Elin Wägner as its first editor.

[1] Nilsson met Aleksandra Kollontaj, a Russian diplomat and later ambassador to Sweden in the early 1930s.