Montclair ( or ) is a township in Essex County, New Jersey, United States. As of the 2010 United States Census, the township's population was 37,669, reflecting a decline of 1,308 (-3.4%) from the 38,977 counted in the 2000 Census, which had in turn increased by 1,248 (+3.3%) from the 37,729 counted in the 1990 Census. As of 2010 it was the 60th-most-populous municipality by population in New Jersey.
Montclair was first formed as a Township on April 15, 1868, from portions of Bloomfield Township, so that a railroad could be built to Montclair. After a referendum held on February 21, 1894, Montclair was reincorporated as a Town, effective February 24, 1894. In the late 1970s, after protesting for years at the inequities built into the formulas, Montclair joined several other communities to qualify for a pool of federal aid allocated only to Townships, that allowed townships to receive as much as double the revenue-sharing aid per capita received by the four other types of New Jersey municipalities — Borough, City, Town or Village.