Carl Friedrich Gauss (1777–1855), German mathematician and scientist who contributed to number theory, analysis, differential geometry, geodesy, magnetism, astronomy and optics.

Sophie Germain (1776-1831), French mathematician who did important work on Fermat's last theorem.

John Graunt (1620-1674), English mathematician who contributed to statistics.

Alexander Grothendieck, German mathematician born in 1928. He made major contributions to algebraic geometry, homological algebra, and functional analysis.