Pioneering Women in American Mathematics: The Pre-1940 PhD's is a book on women in mathematics. It was written by Judy Green and Jeanne LaDuke, based on a long study beginning in 1978, and was published in 2009 by the American Mathematical Society and London Mathematical Society as volume 34 in their joint History of Mathematics series. Unlike many previous works on the topic, it aims at encyclopedic coverage of women in mathematics in the pre-World War II United States, rather than focusing only on the biographies of individual women or on collecting stories of only the most famous women in mathematics. The Basic Library List Committee of the Mathematical Association of America has strongly recommended its inclusion in undergraduate mathematics libraries.