Ocean Grove was founded in 1869 as an outgrowth of the camp meeting movement in the United States, when a group of Methodist clergymen, led by William B. Osborn and Ellwood H. Stokes, formed the Ocean Grove Camp Meeting Association to develop and operate a summer camp meeting site on the New Jersey seashore. The community's land is still owned by the camp meeting association and leased to individual homeowners and businesses. Ocean Grove remains the longest-active camp meeting site in the United States.
As of the census of 2000, there were 4,256 people, 2,331 households, and 785 families residing in the CDP. The population density was 4,564.6/km² (11,956.5/mi²). There were 3,156 housing units at an average density of 3,384.8/km² (8,866.3/mi²). The racial makeup of the CDP was 93.14% White, 3.95% African American, 0.09% Native American, 0.96% Asian, 0.02% Pacific Islander, 0.92% from other races, and 0.92% from two or more races. Hispanic or Latino of any race were 3.62% of the population.
There were 2,331 households out of which 10.0% had children under the age of 18 living with them, 23.6% were married couples living together, 7.7% had a female householder with no husband present, and 66.3% were non-families. 56.6% of all households were made up of individuals and 14.5% had someone living alone who was 65 years of age or older. The average household size was 1.67 and the average family size was 2.59.
In the CDP the population was spread out with 9.9% under the age of 18, 5.8% from 18 to 24, 33.5% from 25 to 44, 26.4% from 45 to 64, and 24.4% who were 65 years of age or older. The median age was 45 years. For every 100 females there were 82.4 males. For every 100 females age 18 and over, there were 81.1 males.
The median income for a household in the CDP was $31,935, and the median income for a family was $58,583. Males had a median income of $38,389 versus $31,886 for females. The per capita income for the CDP was $26,232. About 5.1% of families and 13.3% of the population were below the poverty line, including 12.0% of those under age 18 and 5.5% of those age 65 or over.
However, because Ocean Grove is a summer resort community and many residences are thus unoccupied during the winter months, these statistics may not be representative of the actual population at all times of the year.