Lake Mary Ann, reservoir near Tennant Creek, Northern Territory, Australia

Lake Mary Ann is a reservoir near Tennant Creek with gentle banks and clear water suitable for swimming and relaxation. The site features shaded areas, picnic tables, walking paths around the dam, and a bike track connecting to town.

The Warumungu lived at Tingkkarli for thousands of years before the site was pegged as mining lease GML441E by Nugget Wilson, Bill Howes and Harold Williams. In 1977 residents proposed a recreational dam; construction ran from 1979 to 1980, the wall was completed in April 1980, the reservoir filled in January 1981 and was opened on 24 April 1981 by Ian Tuxworth. It was renamed Lake Mary Ann on 7 December 2005.

The Warumungu name for the lake is Tingkkarli, and the Warumungu people have lived in the area for thousands of years. In 2014 the Federal Court determined seven native title claims covering 37,000 square kilometres around the lake.

The reservoir lies about 5 km north of Tennant Creek, just off the Stuart Highway. Swimming and canoeing are possible, with landscaped grass on one side and natural bushland on the other. The dam wall is 11 m high and 143 m long.

The name comes from the Mary Ann mine, pegged as GML441E by Nugget Wilson and Bill Howes with Harold Williams; Wilson and Howes named it after their daughters Mary Jean and Wendy Ann. The watercourse became Mary Ann Creek, and the reservoir kept the name until it was renamed Lake Mary Ann on 7 December 2005.