Glenmere Lake is a colonial mill pond or reservoir located in Orange County, New York, United States.

It is New York State's largest habitat[2] of the Northern cricket frog (Acris crepitans), listed as endangered by in New York State Department of Environmental Conservation records[3] The lake is part of the greater Orange County-owned Glenmere Preserve, one of the largest wild areas in Orange County.

Glenmere Lake is the most biologically diverse natural feature of Orange County, with hardwood swamp, shale ridgelines, wide marsh, mossy bogs, vernal pools and an open-water reservoir.

The lake and associated county lands comprise sections of the towns and villages of Warwick, Chester, Sugar Loaf and Florida.

[2] After a number of years of warnings associated with the condition of and repairs to the Glenmere Lake dam, a penalty of $350,000 was assessed against the town of Chester and village of Florida by state regulators.