The Golden Gate Bridge is a suspension bridge spanning the Golden Gate, the opening of the San Francisco Bay onto the Pacific Ocean. As part of both US Highway 101 and California Route 1, it connects the city of San Francisco on the northern tip of the San Francisco Peninsula to Marin County.

The Golden Gate Bridge had the longest suspension bridge span in the world when it was completed in 1937 and has become an internationally recognized symbol of San Francisco and California. Since its completion, the span length has been surpassed by eight other bridges. It still has the second longest suspension bridge main span in the United States, after the Verrazano-Narrows Bridge in New York City. In 2007, it was ranked fifth on the List of America's Favorite Architecture by the American Institute of Architects.

The Golden Gate Bridge spans the Golden Gate, a narrow, 400-foot (120 m) deep strait that serves as the mouth of the San Francisco Bay, between San Francisco at the northernmost tip of the San Francisco Peninsula, and the Marin Headlands at the far southern end of Marin County. Although close by proximity, the two sides of the strait are separated by significant natural obstacles. Crossing the strait directly by boat is dangerous because of strong currents and lack of suitable landings. Ocean tides drive an average of 528 billion gallons (2 billion cubic meters) of water every six hours, at peak currents exceeding 5.6 miles per hour (2.5 m/s). Circumnavigating the Bay, however, involves a trip of several hundred miles and crossing several major rivers.