Katherine Freese earned her physics degrees from Princeton (where, as far as she knows, she was the second woman to major in physics), Columbia and Chicago, then did postdocs at the Harvard-Smithsonian Center for Astrophysics, the Kavli Institute for Theoretical Physics and the University of California, Berkeley. She has held faculty positions at MIT and Michigan, and been a visiting faculty member at the Max Planck Institute für Physik, Columbia, UC Berkeley and the Perimeter Institute for Theoretical Physics. She works on a wide range of topics in theoretical cosmology and astroparticle physics. She has been working to identify the dark matter and dark energy that permeate the universe as well as to build a successful model for the early universe immediately after the Big Bang. She has shown that most of the mass in galaxies does not consist of ordinary stellar material, and has proposed ways to look for alternatives such as supersymmetric particles. Recently she has proposed that “dark stars” were the first stars to form in the Universe. Email: ktfreese@umich.edu. Web: http://www-personal.umich.edu/~ktfreese/.