The Math-Blog presents a nice overview of some of the greatest female mathematicians ever. No doubt, most of the mathematicians we ever hear of are men, but there still are several female mathematicians that have made significant contributions to the field. Here is part of the introduction to this list of mini-biographies:

These women were often groundbreakers, highly determined and very dedicated. They are shining examples of the fact that mathematics is not a “boys only” club, even if at many points in time it’s appeared that way on the surface. Today their work is recognized and appreciated, and they stand as fantastic sources of inspiration for a new generation of students and math enthusiasts – both female and male.