High Park is a municipal park in Toronto, Ontario, Canada. High Park is a mixed recreational and natural park, with sporting facilities, cultural facilities, educational facilities, gardens, playgrounds and a zoo. One-third of the park remains in a natural state, with a rare oak savannah ecology. High Park was opened to the public in 1876 and is based on a bequest of land from John George Howard to the City of Toronto. It spans 161 hectares (400 acres) and is one of the largest parks in Toronto.

High Park is located to the west of downtown Toronto, north of Humber Bay, and is maintained by the City of Toronto Parks Department. It stretches south from Bloor Street West to The Queensway, just north of Lake Ontario. It is bounded on the west by Ellis Park Road and Grenadier Pond and on the east by Parkside Drive.

The landscape in the park is hilly, with two deep ravines extending the full north–south distance of the park. Significant natural parts of the park are classified as a provincial Area of Natural and Scientific Interest.

The eastern ravine is a north–south ravine occupying the eastern half of the park along a small creek and several ponds. A forested area begins at the north-east corner of the park, at Bloor Street and Parkside Drive. The creek begins at spring-fed ponds, Howard Pond, and Ridout Pond and flows south through the ravine along Spring Creek Road. Halfway to the southern boundary of the park, the ravine is less forested with picnic areas, the adventure playground, and the zoo. Upper Duck Pond, just to the west of the adventure playground, often has several species of ducks, including wood ducks to be seen. The pond was one of the first locations where bird banding was done, marked by a plaque. Great blue herons can sometimes be seen there and at Lower Duck Pond, just north of The Queensway, where the water drains in pipes south to Lake Ontario.

The eastern ravine lies over a buried river. In 2003, city workers found strong evidence of the pre-ice-age Laurentian River when capping two artesian wells at the pond at the north-east corner of the Park. The wells began spewing a plume of water, sand, shale and gravel 15 metres into the air. With this discovery, geologists finally pinpointed the southern terminus of this ancient river system whose southerly flow begins near Georgian Bay. The watercourse, flowing 50 metres (160 ft) below the surface in pure bedrock, has remained undisturbed for thousands of years.

The central section is a large plain encompassing most of the northern boundary, slowly narrowing to a point overlooking the lake, which is the location of Colborne Lodge. While most of the plain is developed for picnicking, gardens and sports fields, it has a stretch of open habitat called oak savannah, of which there are few other examples in Ontario. The towering black oak trees found throughout High Park are a characteristic of this habitat. Many of the trees are over 150 years old. The savannah is under the special care of the City and volunteer conservationists. Forested areas of High Park are maintained to mimic natural conditions, with downed trees left to decay. Regular controlled burns are done to mimic forest fires and their beneficial effects for oaks. Non-native plants outside the ornamental gardens are weeded out by volunteers. There is, however, no shortage of non-native trees including Colorado spruce, Scots pine and Northern catalpa.

Grenadier Pond is a large body of water 14.2 hectares (35 acres) in size, located on the western edge of the park. It is named after the local Town of York garrison of the 1800s and their use of the pond for fishing. There are two local myths circulating about the pond. One is that British Grenadiers fell through its thin ice when crossing to defend the city in the War of 1812. However the Grenadier Guards were not stationed at Fort York at this time, but rather the 8th (The King's) Regiment of Foot which are not linked to the Grenadier name. Most British infantry regiments grouped the largest and strongest men together during this period to form units of 'Grenadiers', who would form on the right flank of their parent regiment. Other myths include that the pond is 'bottomless', that is, its depth cannot be measured due to the amount of mud. Fishing remains a popular pastime. Largemouth bass, black crappie, yellow perch, pumpkinseed, bluegill, brown bullhead and carp sport fish are present in the pond. Fish caught in the pond are safe to eat, and fishing derbies and casting contests have been held there.

Initiatives have been made to improve the pond's health and environment. Grenadier Pond receives some of its water from Wendigo Creek (a small creek that began near Dundas Street West and Law Street and ran down to a sandbar to Lake Ontario) to Wendigo Pond and underground streams feeding it from the north. The northern end of the Pond was naturalized, building a wetland to filter the waters the Pond receives from the stream. The southern and south-western shore of the pond was also naturalized, removing the manicured lawn and concrete bank to improve the Pond's health and discourage Canada geese. Signs now ask people not to feed the waterfowl. Grenadier Pond is home to multiple species of bird and marsh wildlife. The pond exits out to Lake Ontario via pipes near Sir Casimir Gzowski Park, replacing the natural sandbar that existed for Wendigo Creek. Alongside its eastern shore are to be found High Park's hillside gardens and a grove of cherry trees.