Port Neches is a city in Jefferson County, Texas, United States. The population was 13,040 at the 2010 census, down from 13,601 at the 2000 census. It is part of the Beaumont–Port Arthur metropolitan area.
The area known as Port Neches was once inhabited by tribes of the coastal-dwelling Karankawa and Atakapa Native Americans. Smith's Bluff (the future site of Sun Oil and Union Oil of California riverside property) and Grigsby's Bluff (now Port Neches) were the only two high land bluffs on the Neches River south of Beaumont. Before 1780, Grigsby's Bluff, specifically that part of Port Neches immediately east of Port Neches Park, had been a Native American town for at least 1,500 years, at first of the Karankawa tribe, whose 7-foot (2.1 m) skeletons were often found in the burial mounds there; and after 1650 of the Nacazils, a sub-tribe of the Attakapas, who were a short and stocky people before their extinction about 1780. As of 1841, there were six large burial mounds at Grigsby's Bluff, size about 60 feet (18 m) wide, 20 feet (6.1 m) tall, and 100 yards (91 m) long, consisting entirely of clam and sea shells, skeletons, pottery shards, and other Native American artifacts. Between 1841 and 1901, all six of the mounds disappeared, a result of human actions. Grigsby's Bluff became a post office in 1859 (there was also a store and sawmill there), but the office was discontinued in 1893.
Port Neches was the site of Fort Grigsby, a set of Civil War-era defenses intended to stop a Union advance up the Neches River. The fort was constructed in October 1862 and abandoned sometime after July 1863.