Port Arthur is a city in the U.S. state of Texas, 90 mi (140 km) east of Houston. Part of the Beaumont–Port Arthur metropolitan area, Port Arthur lies primarily in Jefferson County, with a small extension in Orange County. The largest oil refinery in the United States, the Motiva Refinery, is located there.

The population of Port Arthur was 53,818 at the 2010 census, down from 57,755 at the 2000 census. By 2020, its population had rebounded to 56,039. Early attempts at settlements in the area had all failed. However, in 1895, Arthur Stilwell founded Port Arthur, and the town quickly grew. Port Arthur was incorporated as a city in 1898 and soon developed into a seaport. It eventually became the center of a large oil refinery network. The Rainbow Bridge across the Neches River connects Port Arthur to Bridge City.

Port Arthur is vulnerable to tropical cyclones and the city has been extensively damaged by tropical cyclones several times.

Aurora was an early settlement attempt near the mouth of Taylor Bayou on Sabine Lake, about 14 miles (23 km) long and 7 miles (11 km) wide. It is a saltwater estuary formed by the confluence of the Neches and Sabine Rivers. Through its tidal outlet, 5-mile-long (8 km) Sabine Pass, Sabine Lake drains some 50,000 sq mi (100,000 km2) of Texas and Louisiana into the Gulf of Mexico.

The town was conceived in 1837, and in 1840 promoters led by Almanzon Huston were offering town lots for sale. Some were sold, but Huston's project failed to attract many settlers. The area next was known as "Sparks", after John Sparks, who moved his family to the shores of Sabine Lake near the site of Aurora. The Eastern Texas Railroad, completed between Sabine Pass and Beaumont, Texas, passed 4 miles (6 km) west of Sparks. However, the American Civil War soon began, and rail lines were removed. In 1886, a destructive hurricane hit the coast, causing the remaining residents to dismantle their homes and move to Beaumont. By 1895, Aurora had become a ghost town.

Arthur Stilwell led the resettling of the area as part of his planned city as the southern terminus of his Kansas City, Pittsburg and Gulf Railroad, predecessor to the Kansas City Southern Railway. Stilwell named the city Port Arthur after himself, not the British Royal Navy Lieutenant who gave his name to Port Arthur, China.

Pleasure Island now separates the city from the Gulf Intracoastal Waterway. The 18.5-mile (29.8 km) man-made island was created between 1899 and 1908 by the Corps of Engineers to support development of the port.

Arthur Stilwell founded the Port Arthur Channel and Dock Company to manage the port facilities. The port officially opened with the arrival of the British steamer Saint Oswald in 1899.

When oil was discovered at Spindletop, the J.M. Guffey Petroleum Company, later Gulf Oil, had run pipelines to Port Arthur as a shipping point and a location for an oil refinery. In November 1901, the first tanker, the Cardium, departed with Spindletop oil. The refinery was enlarged in 1902, and a pipeline connected to the Glenn Pool Oil Reserve in Oklahoma. The Texas Company, later Texaco, also started building a refinery in 1902. By 1916, the Port Arthur refinery was one of the three largest in the United States.

In 2015, the city council proposed an ordinance to declare Port Arthur a "film friendly city."

In October 2021, Governor Abbott announced that Port Arthur has been declared a "film friendly city" by the Texas Film Commission.

Port Arthur is located on the eastern edge of Jefferson County on the west side of Sabine Lake. It is bordered to the northeast by Orange County, Texas, and to the southeast, across Sabine Lake, by Cameron Parish, Louisiana. The Port Arthur city limits extend south along the west side of Sabine Pass, the outlet of Sabine Lake, as far as the Gulf of Mexico on the city's southern border. To the north, the city limits extend across the Neches River into Orange County. Port Arthur is bordered to the northwest by the cities of Nederland, Groves, and Port Neches, and to the northeast by Bridge City in Orange County.

According to the United States Census Bureau, the city has a total area of 144.1 square miles (373.1 km2), of which 76.9 square miles (199.2 km2) are land and 67.1 square miles (173.9 km2), or 46.61%, are covered by water.

Communities in Port Arthur include:

Celebrations in Port Arthur on completion of the Kansas City, Pittsburg and Gulf Railroad between Kansas City and Port Arthur occurred Saturday, September 11, 1897. The celebrations brought additional people into town. The next day, a major hurricane hit Port Arthur. Water flowed five feet deep in the streets. People loaded into the unfinished railroad roundhouse seeking shelter; the building promptly collapsed, killing four. In the end, 13 people died, homes were destroyed, and a pleasure pier was severely damaged.

In June 1957, Hurricane Audrey made landfall just east of Port Arthur in Cameron Parish, Louisiana, as a category 3 hurricane. The storm caused extensive wind damage around the city and significant storm surge flooding just east in Southwest Louisiana.

On September 24, 2005, Hurricane Rita made landfall between Sabine Pass, Texas, and Johnson Bayou, Louisiana, as a category 3 hurricane. A wind gust of 116 mph (187 km/h) was recorded in Port Arthur. The storm caused widespread significant wind damage throughout the city, with power outages lasting several weeks in some locations. Some areas of the city also received flooding due to Rita.

On September 13, 2007, Hurricane Humberto made landfall west of Port Arthur as a category 1 hurricane. The storm moved northeast across the Golden Triangle, causing widespread wind damage; however, most of the damage was relatively minor. An 84 mph (135 km/h) wind gust was recorded at the Southeast Texas Regional Airport just northwest of the city.

On August 5, 2008, Tropical Storm Edouard made landfall just west of Port Arthur. The effects felt in the city were light; however, wind gusts up to 55 mph (89 km/h) were recorded.

On September 13, 2008, Hurricane Ike made landfall on Galveston Island as a category 2 hurricane. Due to the storm's unusually large size, effects were widespread and were felt across much of Southeast Texas. Port Arthur sustained significant wind damage and many of the city's residents lost power. The Port Arthur seawall protected the city from the major flooding that surrounding cities experienced.

On August 29, 2017, after Harvey made a second landfall at tropical storm status, 26 inches of rain fell in a single day at the airport near Port Arthur, triggering widespread flash flooding in the city. According to the Port Arthur mayor Derrick Freeman, 20,000 homes were flooded with up to 6 ft of water. On August 30, Freeman posted on Facebook, "Our whole city is underwater right now."

Hurricane Laura was expected to make landfall as a major hurricane with Port Arthur in its direct path. Port Arthur was evacuated. However, turning almost due north, Laura ended up making its final landfall near Cameron, Louisiana.

Port Arthur is tied with Lake Charles, Louisiana, and Astoria, Oregon, as the most humid city in the contiguous United States. The average relative humidity is 90% in the morning, and 72% in the afternoon.

At the 2010 census, 53,818 people, 20,183 households, and 13,191 families resided in the city. The population density was 654.6 inhabitants per square mile (252.7/km2). The 23,577 housing units averaged 284.4 per square mile (109.8/km2). At the 2020 census, the population increased to 56,039. The racial makeup of the city was 41.7% African American, 37.9% White, 1.2% Native American, 6.3% Asian, 0.1% Pacific Islander, and 15.3% from other races in 2010. Hispanics or Latino Americans of any race were 29.6% of the population. In 2019, the American Community Survey estimated 18.7% of the population was non-Hispanic white, 38.1% Black and African American, 0.2% Native American, 7.3% Asian, 0.1% Pacific Islander, 0.2% some other race, and 34.5% Hispanic or Latino American of any race.

Of the 20,183 households in 2010, 30.2% had children under the age of 18 living with them, 39.2% were married couples living together, 19.8% had a female householder with no husband present, and 34.6% were not families; 30.1% of all households were made up of individuals, and 11.1% had someone living alone who was 65 years of age or older. The average household size was 2.63 and the average family size was 3.31. In the city, the population was distributed as 27.0% under the age of 18, 9.7% from 18 to 24, 24.7% from 25 to 44, 25.2% from 45 to 64, and 13.3% who were 65 years of age or older. The median age was 35.3 years. For every 100 females, there were 96.9 males. For every 100 females age 18 and over, there were 94.1 males.

From 2014 to 2019, the median household income was $36,557; families had a median income of $44,115; married families $56,304; and non-family households $24,280. Among the population, 27.2% lived at or below the poverty line, against the state's 13.6% impoverished population from 2014 to 2019 census estimates. In contrast, the nearby city of Beaumont had a poverty rate of 16.7%, down from 17.6%.

Home to a large portion of United States oil refining capacity, Port Arthur has seen renewed investment in several key installations. Motiva Enterprises began undertaking a major addition to its western Port Arthur refinery, expanding capacity to 600,000 barrels per day (95,000 m3/d). This $10.0 billion project is the largest U..S refinery expansion to occur in 30 years. Premcor Refining (now Valero) completed a $775 million expansion of its petrochemical plant, and BASF/Fina commenced operations of a new $1.75 billion gasification and cogeneration unit on premises of its current installation, which had just completed its own $1 billion upgrade. These operations are supported by the Port of Port Arthur, one of Texas' leading seaports.

The city was the site of an oil spill in 2010, when an oil tanker and barge collided, causing 450,000 gallons of oil to spill into the Sabine/Neches waterway alongside the city.

The commercial center of Port Arthur was at its peak in the early 1900s. Together with the effects of suburbanization, which drew off wealthier residents to new housing away from town, gradually taking businesses with them, from 1960 until 1974, successive waves of economic recession caused much distress in the town. The central business district has many boarded up and vacant locations.

The Hotel Sabine opened at 600 Proctor Street in 1929 and operated as the Vaughn Hotel until the mid-1930s. At 118 feet, 10 stories, and the tallest building in Port Arthur, the building is of Beaux-Arts architecture style, built with steel-reinforced concrete and brick on 640 steel-laced wooden cypress pilings driven 60 ft into the ground. It was overdesigned and overbuilt due to lack of knowledge on the strength of concrete in the 1920's. The hotel closed down in the mid-1980s.

The Port Arthur News reported August 28, 2010, that "DWA (Digital Workforce Academy) Buys Sabine Hotel", By November 2011, the hotel was reported to be slated for demolition. The cost of renovations were estimated at $10–12 million and demolition estimates as $500,000 to $1.2 million. As of April, 2021, Motiva was still considering buying the hotel, but remained uncertain and uncommitted to it.

Hurricane Rita struck a direct hit on the Proctor Street Seawall, and damaged many downtown businesses and homes. As economic activity picked up in the region, calls for downtown revitalization have been advanced. The true center of commercial activity has gravitated from downtown to other areas. The main shopping center is Central Mall, opened outside the downtown in 1982.

Port Arthur's Museum of the Gulf Coast is recognized as the area's definitive collection of items and displays for figures from Port Arthur and the surrounding communities.

UGK, perhaps Texas's most influential hip-hop group, originated in Port Arthur before relocating to Houston.

The mayor of Port Arthur is Thurman "Bill" Bartie.

The county operates the Jefferson County Sub-Courthouse in Port Arthur.

The United States Postal Service operates the Port Arthur Post Office, the Port Acres Post Office, and the Sabine Pass Post Office in Sabine Pass.

In the Texas State Legislation, Port Arthur is in the 4th Senate District, represented by Republican Brandon Creighton, and in the 22nd State House District, represented by Democrat Christian Manuel while the Sabine Pass portion of Port Arthur is within the 21st State House District, represented by Republican Dade Phelan.

In the United States House of Representatives, Port Arthur is in Texas' 14th congressional district, represented by Republican Randy Weber.

Located in downtown Port Arthur, celebrated its 100th birthday in 2009. Offering a full variety of basic core curriculum classes in which credits are transferable throughout Texas public universities, Lamar State College is recognized for associate programs in commercial music, nursing, legal assistant, and process technology. The college also fields competitive teams in men's basketball and women's softball.

The sections of Port Arthur within the Hamshire-Fannett and Sabine Pass ISDs are assigned to Galveston College in Galveston. State legislation does not specify an assigned community college for the remainder of Jefferson County.

It was formerly named Stilwell Technical Center and is the second college in Port Arthur. The Port Arthur Independent School District is now headquartered at its former location on 9th Avenue. In 2012 the school was relocated to a new building built on the same property of Memorial High School at 3501 Sgt Lucian Adams Dr.

Most of the city is served by the Port Arthur Independent School District. It operates a single high school, Memorial High School, formed in 2002 by the consolidation of three high schools: Stephen F. Austin, Abraham Lincoln, and Thomas Jefferson.

The portion around Southeast Texas Regional Airport is served by the Nederland Independent School District. Some parts are served by Port Neches-Groves Independent School District. The Sabine Pass community is served by the Sabine Pass Independent School District. There are portions of Port Arthur in Nederland ISD, Beaumont ISD, and Hamshire-Fannett ISD. In Orange County, the portions of Port Arthur are in Bridge City Independent School District.

The Bob Hope Charter School is located in Port Arthur.

It formerly had a Catholic high school, Bishop Byrne High School, which closed in 1983.

The Port Arthur Public Library, at 4615 9th Avenue at Texas State Highway 73, serves as the public library system for the city.

The Port Arthur News is the only daily newspaper serving Port Arthur. Operating since 1897 The News is one of the oldest continually operated businesses in Port Arthur. It is currently owned and operated by Boone Newspapers. From 1932–1941 Port Arthur had a second newspaper called The Peoples Press.

The Jack Brooks Regional Airport in the northwest part of Port Arthur serves Beaumont and Port Arthur.

Local bus service is provided by Port Arthur Transit.