Ada Margaret Brayton (December 27, 1885 – January 1975) was a life member of the American Astronomical Society, and co-author of the monumental book, Spectroscopic Absolute Magnitudes and Distances of 4719 Stars that increased the number of stars of known distance one hundred-fold.

Ada Margaret Brayton was born in Nebraska, the daughter of Franklin B. Brayton and Grace Treloar.^[1]

She was a member of the staff of Mount Wilson Observatory, the Astronomical Computer Department of stellar spectroscopy. She was a life member of the American Astronomical Society and member of the Archaeological Society of New Mexico.^[1] In 1920 she found that the radial velocity of the star Boss 3644 was variable thanks to her measures of three spectrograms made with the 60-inch reflector and single prism spectrograph.^[2] In 1935, Brayton, together with Walter Sydney Adams, Alfred H. Joy (1882-1973), and Milton La Salle Humason (1891-1972), published a monumental book, Spectroscopic Absolute Magnitudes and Distances of 4719 Stars that increased the number of stars of known distance by one hundred-fold.^[3]

She was an accredited teacher, translator and interpreter of Spanish.^[1]

She was the first vice-president of California Federation of Business & Professional Women's Clubs and president of Pasadena Business and Professional Women's Club from 1928 to 1929.^[4][1][5]

She was the president of the Pasadena Chapter of the Grenfell Association of America.^[1]

She was a member of the Lucretia Garfield Circle and the Ladies of G. A. R.^[1]

She lived at 469 Ladera Street, Pasadena, California,^[1] with her brother, Wilbur Newman Brayton (died 1940), a veteran of World War I.^[6]

In 1924 The Ada Margaret Brayton Endowment Fund of $20,000.00 ($279,112.14 in 2017)^[7] was established to be used for the best interest of the California Federation of Business and Professional Women's Clubs, Inc. ^[8]