Lake Red Rock, also referred to as Red Rock Reservoir is a reservoir formed by Red Rock Dam on the Des Moines River, about 41 miles (66 km) southeast of the city of Des Moines, Iowa, U.S.

The dam was completed in 1969 as a Flood control project by the United States Army Corps of Engineers, creating the largest lake in Iowa.

The lake shore has various recreational activities such as camping, hiking, boating and fishing.

There is also a "water trail", known as the Red Rock Water Trail, where one can float down the Des Moines River from the southeast corner of Polk County to the lake and down to Red Rock Dam.

[1] A major landmark is what is locally called the "Mile Long Bridge", carrying Iowa Highway 14 at its upstream end.