Ellen Fries (23 September 1855 at Rödslegård in Törnsfall, Kalmar län – 31 March 1900 in ) was a Swedish feminist and writer. She became the first female Ph.D. in Sweden in 1883.
She was the daughter of Colonel Patrik Constantin Fries and Beata Maria Borgström. She studied at the Åhlinska flickskolan, and graduated with a professional degree from Wallinska skolan in Stockholm 19 May 1874. She studied language and art by travelling to Paris and Leipzig and was a language teacher at Wallinska skolan in 1875-1877. The universities in Sweden had been opened to both genders in 1870. Fries enlisted as a student at Uppsala University 12 October 1877. She studied history, Nordic language and political science and was given the scholarship Kraemerska stipendiet. She became the first female Ph.D. in Sweden 31 May 1883. She was a teacher in history at Wallinska skolan in Stockholm 1884-1886 and at Åhlinska flickskolan from 1885; in 1890, she became its principal.
In 1884, she was one of six to summon the first meeting of the feminist movement Fredrika-Bremer-förbundet; she initiated the foundation of Svenska kvinnors nationalförbund (Swedish Council of Women) in 1896, and one of the five co-founders of the Nya Idun society.
From 1881, she was active in the feminist paper of Sophie Adlersparre, Tidskrift för hemmet, mainly contributing with biographies of women, and she was also joint editor of the paper in 1883-85. She contributed with articles as a freelancer to various papers, such as Dagny (magazine) 1886–95, Framåt (paper) 1886, Verdandi (paper) 1888, Hemåt (paper) 1892, Nya Idun 1891–92, 1884–85 and Aftonbladet 1885 as well as in the dictionary Nordisk Familjebok.