Bay Farm Island Bridge, Transportation bridge in Alameda, United States.

The Bay Farm Island Bridge, also called the San Leandro Bay Bridge, is a single-leaf bascule drawbridge over the San Leandro Channel, carrying California State Route 61 between Alameda and Bay Farm Island. Its bascule span is 125 feet (38 m) long and lifts a 1,100-short-ton counterweight; the main pier was the largest cofferdam on a state highway since the Bay Bridge.

A wooden trestle bridge was first built at this location in 1854 to cross the channel. The current steel structure was completed in 1953, replacing several earlier versions of the crossing.

The bridge's name honors Bay Farm Island, the Alameda community it links to the main island. In 1899, customs officers ambushed vegetable farmer Mr. Gighilone here, suspecting peddlers of smuggling opium from Bay Farm Island to Alameda and on to San Francisco; he thought he was being robbed and fled until shots stopped him.

The bridge regularly opens to allow sailboats and vessels to pass underneath, so drivers should plan travel times accordingly. Crossing is best timed outside scheduled opening periods to avoid waiting.

The 1995 bicycle bridge is mechanically linked to the road bridge, so it opens whenever the road span lifts. It can also be opened by hand on its own. It runs on two hydraulic pistons and two 50-horsepower motors, unlike the gear-driven drawbridges elsewhere around Alameda, and is the only pedestrian bascule bridge in the United States.