Zavikon Island refers to either the larger or the pair of islands in the Thousand Islands archipelago on the St. Lawrence River between New York and Ontario, two kilometres (1¼ miles) southeast of Rockport, Ontario and approximately 200 metres (660 ft) north of the international boundary.
Zavikon Island is located in Canadian territory and is part of the township of Leeds and the Thousand Islands in the United Counties of Leeds and Grenville.
It has a US-Canada Boundary Commission reference monument, from which surveying measurements are used to calculate the international border line turning point at this section of the river.
In this case, the international border's turning point is approximately 140 metres (460 ft) southeast of the southern tip of Little Zavikon Island as shown on the largest scale USGS map of the area.
A popular misconception is that the larger island is in Canada while "Little Zavikon Island" is in the United States, and that the footbridge between them is the shortest international bridge in the world.