Buffalo Bayou is a slow-moving body of water which flows through Houston in Harris County, Texas. Formed 18,000 years ago, it has its source in the prairie surrounding Katy, Fort Bend County, and flows approximately 53 miles (85 km) east through the Houston Ship Channel into Galveston Bay and the Gulf of Mexico. In addition to drainage water impounded and released by the Addicks and Barker reservoirs, the bayou is fed by natural springs, surface runoff, and several significant tributary bayous, including White Oak Bayou, Greens Bayou, and Brays Bayou. Additionally, Buffalo Bayou is considered a tidal river downstream of a point 440 yards (400 m) west of the Shepherd Drive bridge in west-central Houston.

Houston is the most populous city in the U.S. state of Texas and in the Southern United States. Located in Southeast Texas near Galveston Bay and the Gulf of Mexico, it is the seat and largest city of Harris County; as well as the principal city of the Greater Houston metropolitan area, which is the fifth-most populous metropolitan statistical area in the United States and the second-most populous in Texas after Dallas–Fort Worth. With a population of 2,302,878 in 2022, Houston is the fourth-most populous city in the United States after New York City, Los Angeles, and Chicago, and the seventh-most populous city in North America. Houston is the southeast anchor of the greater megaregion known as the Texas Triangle.