Laguna de los Padres is a freshwater lake located approximately 12–14 km west of Mar del Plata in the General Pueyrredón district of Buenos Aires Province, Argentina. The lake measures roughly 2,065 meters in length and 1,701 meters in width, covering approximately 319 hectares of water surface within a 695-hectare municipal nature reserve. The bottom is muddy and shallow, with dense aquatic vegetation including algae, rushes, and myriophyllum aquaticum (locally called gambarussa) throughout. The surrounding landscape features eucalyptus and pine woods alongside native shrubs such as colletia paradoxa (curro), with undulating terrain and low hills offering elevated viewpoints over the water.

Kayaking and canoeing are permitted on the lake, and the reserve has a history of hosting competitive rowing and canoeing events, including competitions during the 1995 Pan American Games. Windsurfing is also possible in designated areas. Motorized watercraft with internal combustion engines are not permitted on the lake. Despite aquatic vegetation covering portions of the middle of the lake, navigation remains reasonably feasible. There is a small island connected to shore by a causeway, with a wharf for rowboats.

Access to the reserve is free of charge, though fishing requires a provincial permit. The lake is reachable via National Route 226, with paved access roads at approximately kilometers 12 and 15 from Mar del Plata. Bus line 717 connects Mar del Plata's city center to the reserve and nearby Sierra de los Padres, though schedules should be confirmed locally. A regular car is sufficient for main access roads; rougher unpaved tracks may require a 4x4 vehicle. Amenities within the reserve include designated parking, picnic areas with public barbecue pits (fogones), and restrooms at permitted facilities. Camping La Isla is a camping area within the reserve, though access may be limited to weekends and daytime hours — confirmation with Bomberos Voluntarios de Sierra de los Padres is recommended before visiting.

Pejerrey (Argentinian silverside) is the primary fish species in the lake and is most actively fished during summer as water temperatures rise. Trails around the lake are accessible year-round, with spring bringing native wildflowers to the grassland and curral areas. Swimming directly in the lake is not officially recommended due to water quality concerns.