Sir Thomas Richard Edmund Southwood GOM DL FRS (20 June 1931 – 26 October 2005) was a British biologist, Professor of Zoology and Vice-Chancellor of the University of Oxford. A specialist on entomology, he developed the field of insect ecology and the development of study techniques. He wrote a landmark textbook on Ecological Methods that went into numerous editions. He also was well known for developing the field of entomology through mentorship of a circle of researchers at Silwood Park.