Mary Louise Booth (April 19, 1831 – March 5, 1889) was an American editor, translator, and writer. She was the first editor-in-chief of the women's fashion magazine, Harper's Bazaar.

At the age of eighteen, Booth left the family home for New York City and learned the trade of a vest-maker. She devoted her evenings to study and writing. Booth contributed tales and sketches to various newspapers and magazines but was not paid for them. She began to do reporting and book-reviewing for educational and literary journals, still without any pay in money, but happy at being occasionally paid in books.

As time went on, she received more and more literary assignments. She widened her circle of friends to those who were beginning to appreciate her abilities. In 1859, she agreed to write a history of New York, but even then, she was unable to support herself wholly, although she had given up vest-making and was writing twelve hours a day. When she was thirty years old, she accepted the position of amanuensis to Dr. J. Marion Sims, and this was the first work of the kind for which she received steady payment. She was now able to do without her father's assistance, and live on her resources in New York, though very plainly.

In 1861, at the beginning of the Civil War, she procured the advance sheets, in the French language, of Agénor de Gasparin's Uprising of a Great People. By working twenty hours a day, she translated the whole book in less than a week, and it was published in a fortnight. The book created a sensation among Unionists, and she received letters of thanks for it from U.S. Senator Charles Sumner and President Abraham Lincoln. But again, she received little compensation for her work. While the war lasted, she translated many French books into English, calculated to rouse patriotic feeling, and was, at one time, summoned to Washington, D.C. to write for the statesmen, receiving only her board at a hotel. She was able at this time to arrange for her father the position of clerk in the New York Custom House.

At the end of the civil war, Booth had proved herself so fit as a writer that Messrs. Harper offered her the editorship of Harper's Bazaar – headquartered in New York City – a position in which she served from its beginning in 1867 until her death. She was at first diffident as to her abilities, but finally accepted the responsibility, and it was principally due to her that the magazine became so popular. While keeping its character of a home paper, it steadily increased in influence and circulation, and Booth's success was achieved with that of the paper she edited. She is said to have received a larger salary than any woman in the United States at the time. She died, after a short illness, on March 5, 1889.