Green Lake, Urban lake in Seattle, United States.

Green Lake is a 259-acre freshwater lake in north-central Seattle, its basin carved by the Vashon glacier. It has a mean depth of 13 feet and a maximum depth of 30 feet, and it lacks surface inflows or outflows. A 2.8-mile paved path circles the shoreline, with an outer 3.2-mile unpaved path along the park edge.

Green Lake's basin was dug about 50,000 years ago by the Vashon glacier, which also formed Lake Washington, Union, Bitter and Haller Lakes. David Phillips surveyed the area in September 1855 and called it "Lake Green" for its algae blooms. In 1911 the water level was lowered by 7 feet to create parkland, drying up Ravenna Creek; Ravenna Boulevard now runs over the creek bed.

The lake's English name comes from surveyor David Phillips, who in September 1855 noted its tendency toward algae blooms. Since 1984, the south shore near the fishing pier has hosted an annual floating lantern memorial for victims of the Hiroshima and Nagasaki bombings and all other war victims.

A 2.8-mile paved path circles the lake, with an outer unpaved path of 3.2 miles along the park edge. Bicycles, scooters and roller skates are barred from the paved loop under a long-term temporary restriction, so cyclists use Green Lake Way. The inner path gets crowded; the outer one is quieter.

Prospect Point, a spit of land reaching toward Duck Island, shelters a small patch of water from high winds. The lake's Lushootseed name, dxʷƛ̕əš, has no known meaning, and David Phillips, who surveyed the area in September 1855, first wrote it as "Lake Green" because the water was prone to algae blooms.