Concordia is an unincorporated community and census-designated place (CDP)[8] in Monroe Township, Middlesex County, New Jersey, United States.

[9][10] The CDP is oriented around the age restricted gated community of Concordia.

Concordia is in southern Middlesex County, in west-central Monroe Township.

It is bordered to the north by Wittingham, to the southwest by The Ponds, and to the west by Clearbrook.

[1] The 2010 United States census counted 3,092 people, 2,032 households, and 923 families in the CDP.

Of all households, 50.1% were made up of individuals and 44.0% had someone living alone who was 65 years of age or older.

[11] As of the 2000 United States Census[5] there were 3,658 people, 2,180 households, and 1,351 families living in the CDP.