Theodora Emily Colborn (née Decker; March 28, 1927 – December 14, 2014) was Founder and President Emerita of The Endocrine Disruption Exchange (TEDX), based in Paonia, Colorado, and Professor Emerita of Zoology at the University of Florida, Gainesville. She was an environmental health analyst, and best known for her studies on the health effects of endocrine disrupting chemicals. She died in 2014.

In 1947, Colborn obtained a B.S. in Pharmacy from the College of Pharmacy at Rutgers University and became a pharmacist. In 1981, she graduated from Western State College of Colorado, Gunnison, with an M.A. in Science in freshwater ecology. In 1985, Colborn received a Fellowship from the Office of Technology Assessment, U.S. Congress. From there, in 1987, she joined the Conservation Foundation to provide scientific guidance for the 1990 book, Great Lakes, Great Legacy? in collaboration with the Institute for Research and Public Policy, Ottawa, Canada.

In 1985, at age 58 and as a grandmother, Colborn earned a PhD at the University of Wisconsin–Madison in Zoology (distributed minors in epidemiology, toxicology, and water chemistry). In 1993, she established and directed the Wildlife and Contaminants Program at World Wildlife Fund, US. She also held a chair for three years, starting in 1990, with the W. Alton Jones Foundation.

In 1991, as a fellow of the W. Alton Jones Foundation, she brought a group of 21 scientists with diverse backgrounds together, to attend the first of a series of conferences at Racine, Wisconsin, that became known simply as "Wingspread", about the effects of human exposure to hormone-disrupting chemicals examined in the environment. In 1993, she was given a three-year Pew Fellows Award.

Colborn served on numerous advisory panels, including the U.S. Environmental Protection Agency Science Advisory Board, the Ecosystem Health Committee of the International Joint Commission of the United States and Canada, the Science Management Committee of the Toxic Substances Research Initiative of Canada, the U.S. EPA Endocrine Disruptor Screening and Testing Advisory Committee, and the EPA Endocrine Disruption Methods and Validation Subcommittee. She published and lectured extensively on the consequences of prenatal exposure to synthetic chemicals by the developing embryo and fetus in wildlife, laboratory animals, and humans.

In 2003, at age 76, she founded a non-profit, The Endocrine Disruption Exchange (TEDX), a research organization devoted to understanding how environmental exposures to endocrine disruptors interfere with development and health, for academicians, policy makers, government employees, community-based and health support groups, public health authorities, physicians, the media, and individuals.

In 2005, she first talked about public health issues regarding gas development. Two years later she testified in the US House Committee on Oversight and Government Reform about "the need for full disclosure of chemicals used to produce and deliver natural gas". She continued to work on this topic until her last year of life, when she published a study on air quality near natural gas operations and developed a continuing medical education course titled "Natural Gas Operations, Air Emission Exposure, and Recommendations to the Healthcare Community."

Colborn's 1988 research on the state of the environment of the Great Lakes revealed that apex predator female birds, fish, mammals, and reptiles transferred persistent, man-made chemicals to their offspring, which undermined the development and programming of their youngsters' organs before they were born or hatched. In 1991, in light of this evidence, Colborn convened 21 international scientists from 15 different disciplines to share their research relevant to transgenerational health impacts. The Wingspread statement contains participant and specialty information. During that meeting, the term “endocrine disruption” was coined.