The location of what is now Syosset was originally inhabited by MatinecockNative Americans. In the 17th century, European colonists – primarily the Dutch and English – began to settle the area.
In 1962, Syosset Hospital – the hamlet's local hospital – was established. Located on Jericho Turnpike (NY 25), the hospital's opening provided the growing suburban community with improved, local medical care and facilities.
According to the U.S. Census Bureau, Syosset has a total area of 5.0 square miles (13km2), all land. Syosset absorbed the hamlet and former CDP of Locust Grove for the 1990 census.
The CDP gained some territory from the village of Muttontown between the 2000 census and 2010 census, and also lost some territory, which was annexed to the village of Laurel Hollow.
Syosset is served by the Syosset LIRR station, the Syosset Post Office, the Syosset Central School District, the Syosset Public Library, and the Syosset Fire Department. It is additionally served by the Jericho Water District – except for a small portion at the CDP's southeastern edge, which is instead within the Plainview Water District.
Greater Syosset area
The Greater Syosset area consists of 2 villages and 2 unincorporated hamlets
As of the 2020 census, Syosset had a population of 19,259. The median age was 43.0 years. 25.4% of residents were under the age of 18 and 17.1% of residents were 65 years of age or older. For every 100 females there were 97.2 males, and for every 100 females age 18 and over there were 93.5 males age 18 and over.
100.0% of residents lived in urban areas, while 0.0% lived in rural areas.
There were 6,033 households in Syosset, of which 44.1% had children under the age of 18 living in them. Of all households, 73.4% were married-couple households, 8.1% were households with a male householder and no spouse or partner present, and 16.1% were households with a female householder and no spouse or partner present. About 12.4% of all households were made up of individuals and 8.2% had someone living alone who was 65 years of age or older.
There were 6,293 housing units, of which 4.1% were vacant. The homeowner vacancy rate was 1.4% and the rental vacancy rate was 8.4%.
The median income for a household in Syosset was $180,297, and the median income for a family was $223,508. Males had a median income of $109,742 versus $77,038 for females. The per capita income for Syosset was $78,230. About 1.6% of families and 2.8% of the population were below the poverty line, including 2.4% of those under age 18 and 4.3% of those age 65 or over. The median home value is $944,786, while the average listing price of a home in the CDP was $1,164,815.
Education
Syosset High School in 2021
Syosset is located almost entirely within the Syosset Central School District, spare for a small part of its northwestern tip, which is located within the Oyster Bay-East Norwich Central School District. Accordingly, children residing within Syosset who attend public school go to school in one of these two districts, depending on where they live within the CDP.
In Soapdish, Whoopi Goldberg's character reveals that Montana Moorhead was formerly Milton Moorhead of Syosset.
In the Comedy Central show Review (season 1, episode 3) the viewer question about pancakes comes from "Nick from Syosset, New York".
In the 2021 television series Gossip Girl, the character Julien Calloway turns down a sponsorship from a strip mall in Syosset in the first episode of season 1.
The Syosset Fire Department (SFD) consists of five all-volunteer fire companies and one all-volunteer EMS company. The SFD operates out of three fire stations, located throughout the area which encompasses Syosset, Woodbury, and parts of Muttontown, Oyster Bay Cove, Laurel Hollow, Cold Spring Harbor, East Norwich, Jericho, Hicksville, and Plainview. With a territory of 17.5 square miles (45km2), the department is the largest in Nassau County by coverage area. They operate a fire apparatus fleet of five engines, one reserve ladder, one truck, one rescue, three ambulances, and several special, support, and reserve units.