Theodore Roosevelt Lake (usually called Roosevelt Lake, sometimes Lake Roosevelt) is a large reservoir formed by Theodore Roosevelt Dam on the Salt River in Arizona as part of the Salt River Project (SRP). Located roughly 80 miles (130 km) northeast of Phoenix in the Salt River Valley, Theodore Roosevelt is the largest lake or reservoir located entirely within the state of Arizona (Lake Mead and Lake Powell are larger but both are located partially within the neighboring states of Nevada and Utah respectively). Both the reservoir and the masonry dam that created it, Roosevelt Dam, were named for U.S. President Theodore Roosevelt who dedicated the dam himself in March 1911. Roosevelt Lake is a popular recreation destination within the Tonto National Forest; the facilities located at this lake are managed by that authority.

Satellite image of Theodore Roosevelt Lake and surrounding geographic features

Roosevelt Lake is the oldest of the six reservoirs constructed and operated by the Salt River Project. It also has the largest storage capacity of the SRP lakes with the ability to store 1,653,043 acre feet (2.039 km3) of water when the conservation limit of Roosevelt Dam is reached. When the dam is in flood-control mode, the lake can store 2,910,200 acre⋅ft (3.590 km3) of water; however, the U.S. Army Corps of Engineers requires all water over the conservation limit to be released from the lake within 20 days.