Susanna Elizabeth Burney, later known as Susan Phillips, was born on January 7, 1755, in King's Lynn, Norfolk, England, the daughter of Dr. Charles Burney (1726–1814), an organist and music historian who published books on the music of France, the Netherlands, Italy, and Germany.

She was an English letter and journal writer. She grew up in London, where she was able to observe the musical life of the capital and to meet the many musicians, men of letters, and artists who visited the family home. In 1764, she went to France with her elder sister Esther Burney (1749-1832) to improve their French. In 1782, she married Molesworth Phillips (1755–1832), a Royal Marines officer who served with Captain Cook on his last voyage. They lived in Surrey and later in rural Ireland. The marriage was unhappy due to her husband's several extramarital affairs and his mistreatment of her. She was interested in music and writing journal letters to her older sister Frances "Fanny" Burney, later Madame d'Arblay (1752-1840). When Fanny secretly wrote and published anonymously her first novel “Evelina” (1778), they were both involved in the cover-up. Susan's letters captured vividly musical life and the personalities involved in it. Her extensive journals and letters provide a striking portrait of social, domestic, and cultural life in London, the Home Counties and Ireland in the late eighteenth century. They are of the great importance and interest to music and theatre historians and contain much significance and interest for Burney scholars, social historians of England and Ireland, women's historians, and historians of the family. Susan Burney Letters Project can be found at the University of Nottingham. Her writings are held by the New York Public Library, the British Museum and Yale University Library.

She died on January 6, 1800, in Parkgate, Cheshire, England.