Glennies Creek Dam, Recreational reservoir in New South Wales, Australia.

Glennies Creek Dam is a 67-metre-high concrete-faced rock-filled embankment dam on Glennies Creek, a Hunter River tributary about 25 km north of Singleton. Its 535-metre crest holds back Lake Saint Clair, which covers 1,540 hectares and reaches 16 km in length at high water.

The Glennies Creek Dam was enabled by the Glennies Creek Dam Act of 1979, which appropriated AU$30 million for construction. Work began in August 1980 and was completed in June 1983, built by Citra Constructions Limited for the NSW Department of Land and Water Conservation and the Department of Water Resources. It supplies water to Singleton and supports irrigation, flood mitigation and coal mining, and is operated together with Glenbawn Dam.

The name Glennies Creek, and the dam, honour James Glennie, a former naval captain granted creek-frontage land near the Hunter River junction in 1824. The reservoir is called Lake Saint Clair. Today the lake is used for swimming, boating, sailing, water skiing and fishing.

The dam lies about 25 km north of Singleton and 39 km upstream of Glennies Creek's junction with the Hunter River. The reservoir, Lake Saint Clair, covers 1,540 hectares with a maximum depth of 56 m. Swimming, boating, sailing, water skiing and fishing take place on the lake. The dam is operated together with Glenbawn Dam to supply water along 40 km of the Hunter River.

The spillway is an unlined cutting in welded ash-flow tuff, and the rock excavated there supplied the entire rock-fill for the dam embankment. Engineers sited it wholly within the welded tuff to avoid the weaker non-welded tuff and sandstone above and below.