Ida Joséphine Phoebe Éva Gauthier (September 20, 1885 – December 20 or 26, 1958) was a Canadian-American mezzo-soprano and voice teacher. She performed and popularized songs by contemporary composers throughout her career and sang in the American premieres of several works by Erik Satie, Maurice Ravel and Igor Stravinsky, including the title role in the latter's Perséphone.

With Zoé, Lady Laurier and Sir Wilfrid Laurier and Lord Strathcona as her patrons, Eva Gauthier initially trained and performed in Europe. She then travelled to Java and for four years immersed herself in its native music, which she introduced to North American audiences on her return. She retired from performing in 1937, and opened a voice studio in New York, where she became a founding member of the American Guild of Musical Artists and served on its board of governors. Gauthier was praised for the many qualities her singing brought to music. The citation from the Campion Society of San Francisco, which she received in 1949, said: "...her rare open-mindedness and unorthodox enthusiasm having been initially responsible for the recognition of many vital and important modern composers".