Anna Blackwell (pseudonym, Fidelitas; 21 June 1816 – 4 January 1900) was a British writer, journalist, and translator who focused on spiritual and social issues. She had a long and successful career as Parisian correspondent of leading colonial papers. She also wrote poetry, fairy tales, and essays on occult subjects. As a teacher and journalist, she exercised a wide influence in the U.S. and in France.