Walden Pond is a celebrated pond in Concord, Massachusetts, in the United States. A good example of a kettle hole, it was formed by retreating glaciers 10,000–12,000 years ago. The pond is protected as part of Walden Pond State Reservation, a 335-acre (136 ha) state park and recreation site managed by the Massachusetts Department of Conservation and Recreation. The reservation was designated a National Historic Landmark in 1962 for its association with the writer Henry David Thoreau (1817–1862), whose two years living in a cabin on its shore provided the foundation for his famous 1854 work, Walden; or, Life in the Woods. The National Historic Preservation Act of 1966 ensured federal support for the preservation of the pond.

Concord is a town in Middlesex County, Massachusetts, United States. In the 2020 census, the town population was 18,491. The United States Census Bureau considers Concord part of Greater Boston. The town center is near where the Sudbury and Assabet rivers join to form the Concord River.