Lake Wanapitei occupies a meteorite crater in Sudbury, Ontario, Canada. It is located near the large Sudbury meteorite crater but is not related to it.

The crater is 5.2 miles (8.37 km) in diameter and the age is estimated to be 37.2 ± 1.2 million years, placing it in the Eocene.

It was evident by the mid-1970s that Wanapitei Lake was an impact crater. Remarkably, it lies on the eastern edge of the much older, larger Sudbury structure. Cobbles of suevite, crumbly impact breccia cobbles containing bits of dark glass, are found surrounding the lake. Some contain coesite, a high pressure mineral diagnostic of impact structures. The suevite is very close in appearance and composition to that described from the Ries impact crater.

The lake is a popular recreational and residential area in Sudbury. With the municipal amalgamation of Greater Sudbury in 2001, it became the largest lake in the world completely contained within the boundaries of a single city. It inherited this status from Lake Ramsey, also in Sudbury.