Galveston Island is a barrier island

Barrier island

Barrier islands, a coastal landform and a type of barrier system, are relatively narrow strips of sand that parallel the mainland coast. They usually occur in chains, consisting of anything from a few islands to more than a dozen...

 on the Texas

Texas

Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

 Gulf coast in the United States, about 50 miles (80 kilometers) southeast of Houston

Houston, Texas

Houston is the fourth-largest city in the United States, and the largest city in the state of Texas. According to the 2010 U.S. Census, the city had a population of 2.1 million people within an area of . Houston is the seat of Harris County and the economic center of , which is the ...

. The entire island, with the exception of Jamaica Beach

Jamaica Beach, Texas

Jamaica Beach is a city in Galveston County, Texas, United States. As of the 2000 census, the city population was 1,075.-History:Prior to its development, Jamaica Beach was a Karankawa burial ground. Johnny Goyen and Earl Galceran of the Jamaica Corporation developed Jamaica Beach as a 2,000-lot...

, is within the city limits of the City of Galveston

Galveston, Texas

Galveston is a coastal city located on Galveston Island in the U.S. state of Texas. , the city had a total population of 47,743 within an area of...

.

The island is about 27 miles (43 kilometers) long and no more than 3 miles (5 kilometers) wide at its widest point. The island is oriented generally northeast-southwest, with the Gulf of Mexico

Gulf of Mexico

The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...

 on the east and south, West Bay

West Bay (Texas)

West Bay, also referred to as West Galveston Bay, is a long inlet of Galveston Bay in Galveston and Brazoria counties that nearly runs the entire length west of Galveston Island.-History:...

 on the west, and Galveston Bay

Galveston Bay

Galveston Bay is a large estuary located along the upper coast of Texas in the United States. It is connected to the Gulf of Mexico and is surrounded by sub-tropic marshes and prairies on the mainland. The water in the Bay is a complex mixture of sea water and fresh water which supports a wide...

 on the north.