The Tropic of Cancer, or Northern tropic, is one of five major degree measures or major circles of latitude that mark maps of the Earth. It is the northernmost latitude at which the Sun can appear directly overhead at noon. This event occurs at the June solstice, when the northern hemisphere is tilted towards the sun to its maximum extent.

The Tropic of Cancer currently lies 23° 26′ 22″ north of the Equator. North of this latitude are the subtropics and Northern Temperate Zone. The equivalent line of latitude south of the Equator is called the Tropic of Capricorn, and the region between the two, centered on the Equator, is known as the Tropics.