Ross Barnett Reservoir, Reservoir in Rankin County, United States.

Ross Barnett Reservoir is a reservoir in Rankin County, Mississippi, formed by a dam on the Pearl River that creates a large body of water with numerous coves and wooded shores. The lake stretches across several counties and includes both open water areas and narrower river channels upstream from the main dam.

Construction of the reservoir began in 1960 under the Pearl River Valley Water Supply District and was completed in 1963, with the lake reaching average capacity in 1965. Its stated purpose was a permanent drinking water source for Jackson, not flood control; the final design could not be purposed as a flood control project. The 3.5-mile earthen dam and its 10-gate spillway release water into the Pearl River.

The name honors a former governor, and today families spend weekends here fishing or boating on the calm water. The shoreline offers picnic spots under trees where groups gather for cookouts, especially during warmer months.

Several access points allow entry to different sections of the lake, with some areas better suited for small boats than others. Most activity happens from spring through fall when the weather is milder and water levels remain stable.

The reservoir holds state fishing records: a 57 lb 12 oz smallmouth buffalo and an 18 lb 14 oz bowfin, and a 65 lb paddlefish was caught at the spillway in 1974. The Bassmaster Classic World Championship was held here in 1978. In late March 2019 anglers reported abundant large black crappie where white crappie usually dominate.