The Governor Malcolm Wilson Tappan Zee Bridge, usually referred to as the Tappan Zee Bridge, is a cantilever bridge in the U.S. state of New York, crossing the Hudson River at one of its widest points; the Tappan Zee is named for an American Indian tribe from the area called "Tappan"; and zee being the Dutch word for "sea". As an integral conduit within the New York Metropolitan Area, it connects South Nyack in Rockland County with Tarrytown in Westchester County in the Lower Hudson Valley.

Federal and state authorities are currently constructing a Tappan Zee replacement bridge that will cost at least $4 billion. There is a toll booth that costs $5 on the eastbound lane.

It is the longest bridge in the State of New York. The total length of the bridge and approaches is 16,013 feet (4,881 m). The cantilever span is 1,212 feet (369 m) providing a maximum clearance of 138 feet (42 m) over the water. The bridge is about 25 miles (40 km) north of Midtown Manhattan, the skyline of which can be seen from the bridge on a clear day.

The Tappan Zee (/ˌtæpən ˈziː/; also Tappan Sea or Tappaan Zee) is a natural widening of the Hudson River, about 3 mi (5 km) across at its widest, in southeastern New York in the United States. It stretches about 10 mi (16 km) along the boundary between Rockland and Westchester counties, downstream from Croton Point to Irvington. It derives its name from the Tappan Native American sub-tribe of the Delaware/Lenni Lenape, and the Dutch word zee, meaning a sea or a wide expanse of water.

Flanked by high steep bluffs of the New Jersey Palisades in the Hudson Valley, it forms something of a natural lake on the Hudson about 10 mi (16 km) north of Manhattan. Communities along the Tappan Zee include Nyack on the western side as well as Ossining and Tarrytown on the eastern side. It is crossed by the Tappan Zee Bridge, opened in 1955 and about 3.1 mi (5 km) long, connecting Nyack and Tarrytown.

On September 14, 1609, the explorer Henry Hudson entered the Tappan Zee while sailing upstream from New York Harbor. At first, Hudson believed the widening of the river indicated that he had found the Northwest Passage. He proceeded upstream as far as present-day Troy before concluding that no such strait existed there.