According to the United States Census Bureau, the CDP has a total area of 2.4 km² (0.9 mi²), all land.
The towns bordering Carle Place are Mineola, Garden City, Old Westbury, East Williston and Westbury.
There were 1,900 households out of which 31.7% had children under the age of 18 living with them, 59.8% were married couples living together, 9.5% had a female householder with no husband present, and 27.8% were non-families. 23.9% of all households were made up of individuals and 10.0% had someone living alone who was 65 years of age or older. The average household size was 2.76 and the average family size was 3.31.
In the CDP the population was spread out with 22.8% under the age of 18, 7.6% from 18 to 24, 29.9% from 25 to 44, 24.4% from 45 to 64, and 15.3% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 91.7 males. For every 100 females age 18 and over, there were 90.7 males.
The median income for a household in the CDP was $70,938, and the median income for a family was $85,240. Males had a median income of $51,745 versus $37,344 for females. The per capita income for the CDP was $31,624. About 3.4% of families and 5.4% of the population were below the poverty line, including 5.1% of those under age 18 and 10.0% of those age 65 or over.
The hamlet draws its name from the Carle House - a 32 room house built by Silas Carle in Westbury in the 1800s. It was called the "Carle Place," and the surrounding area later took the name. An early name (and still-current nickname) for the region is Frog Hollow. As a result, the local high school's sports teams are called the Frogs and the school colors are thus green and white.
In 1946, developer William J. Levitt bought 19 acres for an experiment. His crews brought precut lumber to the site and rapidly assembled 600 low-cost houses on a site near the Carle Place station of the Long Island Railroad, offering affordable suburban living with an easy commute into offices in New York City. Within five years, returning veterans and their families swelled the population by 500 percent. It transformed Carle Place, and served as the prototype for the gargantuan development Levitt began the following year a few miles away: Levittown.
Carle Place has its own school district, which includes small parts of Westbury and Mineola, but is still one of the smallest in New York state. The primary school "Cherry Lane," the elementary school "Rushmore," and the secondary school called "Carle Place Middle/High School" adjoin each other on one campus.
1-800-Flowers is headquartered in Carle Place, New York.