Old Bethpage and its neighboring hamlet, Plainview, share a school system, library, fire department and water district. Law enforcement for the community is provided by the Nassau County Police Department's Eighth Precinct
Powell called his land Bethphage, because it was situated between two other places on Long Island, Jericho and Jerusalem, just as the biblical town of Bethphage (meaning "house of figs") was situated between Jericho and Jerusalem in Israel. Today, the Long Island place formerly called Jerusalem is known as Wantagh and Island Trees, while the placename Jericho is unaltered. Over time, Bethpage was spelled without the second "H". Powell's 14 children split up his purchase and it evolved into several farming communities, and the one in this mostly central part of the purchase retained the name "Bethpage".
A railroad spur completed in 1873, known as the Bethpage Branch of the Central Railroad of Long Island, ran to a brickworks plant which had opened in Old Bethpage in the 1860s. The railway was built to transport bricks for the construction of Alexander Stewart's Garden City. For a few years, regularly-scheduled passenger traffic also appeared in timetables, with the station being called Bethpage. The line was abandoned in 1942. Remnants of a locomotive turntable can be found in the woods of Bethpage State Park on the east side of Round Swamp Road.
In 1908, William Kissam Vanderbilt II began construction of the Long Island Motor Parkway, one of the country's first highways. Eventually stretching 45 miles from Queens, New York to Lake Ronkonkoma, New York, a portion of the parkway ran through Old Bethpage. Street names such as "Vanderbilt Lane", "Motor Parkway" and "Toll Place" serve as reminders. Segments of the old roadbed and some bridges can still be seen in some places, including Battle Row Campground, Bethpage State Park, and the Old Bethpage Village Restoration.
Old Bethpage was home to at least two grand estates, the Benjamin Franklin Yoakum Estate and the Taliaferro Estate.
In 1960, responding to Nassau County's rapid suburban expansion, the county announced plans for the development of the Nassau County Fire Service Academy. Located on Winding Road, the academy provides provides training to all Nassau County fire departments.
According to the United States Census Bureau, Old Bethpage has a total area of 4.1 square miles (10.7 km²). Although Plainview, at 5.7 square miles is 40% larger, its population is appoximately five times that of Old Bethpage because significant portions of Old Bethpage consist of parks and undeveloped property, including, Bethpage State Park, the Old Bethpage Village Restoration and Battle Row Campground.
There were 1,834 households out of which 38.3% had children under the age of 18 living with them, 75.6% were married couples living together, 7.1% had a female householder with no husband present, and 15.1% were non-families. 13.8% of all households were made up of individuals and 10.5% had someone living alone who was 65 years of age or older. The average household size was 2.88 and the average family size was 3.16.
In the CDP the population was spread out with 24.2% under the age of 18, 5.5% from 18 to 24, 27.1% from 25 to 44, 25.1% from 45 to 64, and 18.0% who were 65 years of age or older. The median age was 41 years. For every 100 females there were 91.6 males. For every 100 females age 18 and over, there were 90.5 males.
The median income for a household in the CDP was $89,771, and the median income for a family was $100,325. Males had a median income of $67,917 versus $40,353 for females. The per capita income for the CDP was $34,666. About 2.4% of families and 4.3% of the population were below the poverty line, including 4.0% of those under age 18 and 4.6% of those age 65 or over.
Old Bethpage also had its own one room school house named the Little Red Schoolhouse. This building, which stood until the 1970s, was located on Schoolhouse Road, just off of Round Swamp Road. The building was torn down and the property developed into several houses.
Old Bethpage is home to the Old Bethpage Village Restoration Opened in 1963, on a former Powell family farm, the restoration is an authentic recreation of a mid-19th century Long Island village, complete with farmhouses, a blacksmith, general store, cobbler, school house and church.
Old Bethpage was home to one movie theater, located in the Tru-Value Shopping Center. This theater initially showed first or second run movies. However, in the 1970's it began to show pornographic movies until community protests forced the theater to revert to its original general commercial offerings. The theater eventually closed and remained vacant for a number of years until it was reopened as a live action theater known as the Plaza Playhouse. Today it is known as the Cultural Arts Playhouse, or CAP Center.