Gerald Henry Frazier Gardner (March 2, 1926 – July 25, 2009) was an Irish mathematician, geophysicist and social activist whose statistical analysis led to the banning of classified advertising segregated by gender in a 1973 ruling by the Supreme Court of the United States in the case Pittsburgh Press Co. v. Pittsburgh Commission on Human Relations. On a professional basis, he did early work on the use of monitoring seismological vibrations to identify deposits of natural gas that became industry standards.