Montclair. 1 Residential city (1990 pop. 28,434), San Bernardino co., SE Calif.; inc. 1956. It has some light manufacturing. 2 Town (1990 pop. 37,729), Essex co., NE N.J., a suburb of Newark and New York City, on a slope of the Watchung Mts.; settled c.1666 as part of Newark, set off from Newark 1812, set off from Bloomfield and inc. 1868. Although chiefly residential, it has plants that make chemicals, paint, and metalware. The art museum contains several paintings by George Inness, who lived there. Montclair State Univ. is in Upper Montclair.