Born on 9 September 1893, Marcelle Dauphin was the daughter of Pierre Claudius Alphonse Dauphin and Franziska Kayser de Hollerich. She was the first woman dentist in Luxembourg. She opened her practice in the Rue Notre-Dame in Luxembourg City in 1922.
In 1923, the general practitioner Louise Welter followed.
In the Mémorial du Grand-Duché de Luxembourg of 17 February 1940, she appears on the general list of persons authorised to practise a branch of the healing art or a profession related to it in the Grand Duchy.
Marcelle Dauphin died on 4 May 1976 in Pétange.