The Port of Houston is the port of Houston, Texas, the fourth-largest city in theUnited States. The Port is a 125-mile-long complex of diversified public and private facilities located a few hours' sailing time from the Gulf of Mexico. It is the busiest port in the United States in terms of foreign tonnage, second-busiest in the United States in terms of overall tonnage, and tenth-busiest in the world.

The Port of Houston is made up of the Houston Ship Channel and Galveston Bay. It is made up of the port authority and the 150-plus private industrial companies along the ship channel; many oil companies have built refineries on the channel where they are protected from the Gulf of Mexico. The petrochemical complex associated with the Port of Houston is one of the largest in the world. The port is actually misplaced on Google Earth for this article. The placemark is in Barbours Cut, a small unloading area. The Port of Houston is further north and west.

Approximately 215 million tons of cargo moved through the Port in 2005, about half of which was containerized cargo. The Port has three separate terminals dedicated to the handling of cargo containers: Barbours Cut (the first terminal specifically designed for these shipments), Galveston East End (leased from the Port of Galveston, the Port's long-time rival), and Bayport (opened in October 2006).

The Port offers a 90-minute free cruise aboard the M/V Sam Houston, details of which can be found on its website. Since the Houston Ship Channel is closed to recreational traffic, this is the only means by which the general public can view port operations, and thus the tours are highly popular. Tours are available daily except on Mondays, holidays, and the entire month of September (when the vessel undergoes maintenance).

Most Volkswagen and Audi automobiles sold in North America pass through the port of Houston.

The Port is operated by the Port of Houston Authority, an independent political subdivision of the State of Texas. The Authority is governed by a seven-member Commission. The City of Houston and the Harris County Commissioners Court each appoint two commissioners; these two governmental entities also jointly appoint the chairman of the Port Commission. The Harris County Mayors & Councils Association and the City of Pasadena each appoint one commissioner. Daily operations are overseen by an Executive Director who serves at the will of the Commission.