Green DeWitt (February 12, 1787 – May 18, 1835) was an empresario in Mexican Texas. He founded the DeWitt Colony.
DeWitt was born in Lincoln County, Kentucky, moving with his family while still an infant to Missouri. At the time, Missouri was a part of Spanish-held Louisiana. At 18, he returned to Kentucky, and studied for two years at the college level, then returned to Missouri once again. In 1808 he married Sarah Seely of St. Louis, Missouri, and enlisted in the Missouri militia. He fought in the War of 1812, rising to the rank of Captain by the wars end, then was elected Sheriff of Ralls County, Missouri.
In 1822, DeWitt petitioned the Mexican government for permission to settle colonists in Texas but was denied. After teaming up with Stephen F. Austin, an influential Texas empressario like himself, he finally got the petition granted, in 1825. He was given permission to settle 400 respectable, industrious, Catholic families in an area bounded by the Guadalupe River, San Marcos River, and Lavaca River. This colony was southwest of Austin's. DeWitt hired James Kerr as his surveyor. Kerr placed the capital, called Gonzales after Rafael Gonzales, provisional governor of Coahuila y Tejas, at the confluence of the San Marcos and Guadalupe Rivers. The first settlers arrived in the summer of 1825. DeWitt visited the colony in October, but spent much of 1825 in Missouri recruiting settlers. DeWitt was accused of misappropriation of funds in San Antonio, Texas, by settler Peter Ellis Bean, but was exonerated on October 16, 1825. Sarah DeWitt, whose Brooke County, Virginia family was quite wealthy, contributed to her husband's endeavors, selling off some of her property in Missouri to help finance his venture.