Lake Grove is a village in Suffolk County, New York, United States. The population was 11,163 at the 2010 census. The village is located in the town of Brookhaven. The village is officially known as the Incorporated Village of Lake Grove.
The area of Lake Grove was settled in the early 18th century along Middle Country Road, which was then part of the Old Kings Highway, originally a Native American footpath. The community's first church building, built in 1818, was the First Congregational Church of New Village. Placed on the National Register of Historic Places in 2002, the building has been preserved and is depicted on the village seal. In 1870, Lake Grove established its first post office, which carried the mail to and from Lakeland station (discontinued in 1883) by horse and wagon. The area was variously called Lakeland, Lakeville, New Village, Ronkonkoma or West Middle Island until it settled on the name Lake Grove in mid-19th century, after the groves of trees near Lake Ronkonkoma.During the early 20th century Lake Ronkonkoma became a popular area for recreation, which prompted many small summer houses built on private roads of Lake Grove.