Hypatia
Hypatia was born in Alexandria, Egypt circa 350–370, and died in 415 AD. She was known for her work in philosophy, mathematics, and astronomy and she is the first female mathematician whose life was well-documented.
Rozsa Peter
Rózsa was born Rózsa Politzer in Budapest, Hungary on February 17, 1905, and died on February 16, 1977. She later changed her name to Péter. She is considered one of the founders of the recursive function theory of mathematics.
Julia Robinson
Julia Robinson was born in St. Louis, Missouri in 1919 and died in Oakland, California in 1985. Her area of exploration in mathematics was decision problems.