Mina Kirstein Curtiss was born in Boston, Massachusetts on October 13, 1896 to Louis Kirstein, an optician, and Rose Stein. She had two younger brothers, Lincoln Kirstein, founder and general director of the New York City Ballet, and George Kirstein, publisher of the Liberal Weekly. The family moved to Rochester, NY in 1901 and remained there until 1912, when they returned to Boston and Louis Kirstein became a partner in Filene's Department Store. Curtiss was schooled at home by a governess until 1912, when she was sent to Northampton, Massachusetts to attend Miss Capen's School. She graduated from Smith College in 1918 and went on to earn an MA in English from Columbia University in 1920.

Prior to attending Columbia, Curtiss worked as a research clerk for Military Intelligence in Washington, D.C., from 1918 to 1920. She lived at the headquarters of the National Woman Suffrage Association where she became friends with Anna Howard Shaw and Carrie Chapman Catt. Curtiss married Henry Tomlinson Curtiss in 1926 only to be devastated by his untimely death a year later, in 1927. In 1933 she published The Midst of Life, a book that took the form of a series of letters to her dead husband. From 1922 to 1934 and again from 1940 to 1942, Curtiss was a beloved and highly regarded professor of English at Smith College, returning in 1976, at the age of 81, as Visiting Professor of English Language and Literature to teach a course on writing biography. From 1935 to 1939, she worked with Orson Welles and John Houseman in researching and writing scripts for the Mercury Theatre of the Air. In 1942, she created a program for the Des Moines Register and Tribune radio station, based on soldiers' letters home. This evolved into a book, Letters Home, edited by Curtiss and published in 1944. In 1942 Curtiss also joined the Office of War Information and, with Houseman, developed a short wave radio program for the BBC entitled "Answering You," in which celebrities responded to questions submitted by BBC listeners.

Rather than return to teaching when World War II ended, Curtiss opted to pursue a career in writing, authoring books, journal articles, and book reviews for national and international audiences. She was also fluent in French, and translated and edited works by several noted Frenchmen, including Edgar Degas, Philip Halevy, Marcel Proust, and Alexis Leger (also known as Saint-John Perse). She once said in an interview, "I fall in love with whatever I'm working on," and this passion, combined with a rigorous intellect, made her a tireless, tenacious, and meticulous researcher. Having read Proust and translated his letters for publication in the United States (The Letters of Marcel Proust, 1949), Curtiss was inspired to go to Paris to seek out Proust's family and friends still living, and to unearth more of his correspondence. This research led to publication in 1978 of Other People's Letters: A Memoir and to an interest in the composer Georges Bizet, which Curtiss pursued with characteristic vigor.

Following publication of Other People's Letters: A Memoir in 1978, Curtiss continued to write. She submitted several manuscripts for publication ("Winter Letters," a sequel to Midst of Life; "The Past and I" and "Slices of Life," sequential autobiographies; and "Plato: Archbishop of Moscow," a biographical sketch that evolved from researching A Forgotten Empress: Anna Ivanovich and Her Era, 1730-1740), and to her disappointment all were rejected. Despite a severe heart condition that left her bedridden for the last several years of her life, with the help of her secretary Curtiss continued to edit and modify the manuscripts in hopes that they would eventually go to press.

In addition to teaching and pursuing a career in writing, Curtiss was generous to causes in which she believed, to the extent that her finances allowed. In 1964, she donated most of the land that comprised Chapelbrook, her farm in Ashfield, Massachusetts, to the Trustees of Reservations, before selling the house and remaining acreage privately. She also founded the Chapelbrook Foundation the purpose of which was to provide funding to writers over the age of forty, to enable them to complete works in progress that might otherwise have gone unfinished. Curtiss also donated manuscript material to libraries and repositories, and works of art to museums.

In 1984, Smith College alumnae Anne Morrow Lindbergh and her sister, Constance Morrow Morgan, organized a campaign among Curtiss's former students to raise funds for a tribute to her. The response was overwhelming and led to establishment of the Mina Curtiss Fund, thanks to which a vase of fresh flowers, replaced on a regular basis in perpetuity, graces the Browsing Room in the William Allan Neilson Library at Smith College. Curtiss herself was an avid gardener and, not long before she died, suggested that the tribute take this form.

Mina Kirstein Curtiss died in Connecticut on October 31, 1985.