The City of Orange (known simply as Orange) is a township in Essex County, in the U.S. state of New Jersey. As of the 2020 United States census, the township's population was 34,447, an increase of 4,313 (+14.3%) from the 2010 census count of 30,134, which in turn reflected a decline of 2,734 (-8.3%) from the 32,868 counted in the 2000 census.

The New Jersey Legislature originally incorporated Orange as a township on November 27, 1806, from parts of Newark Township. Parts of the township were taken on April 14, 1834, to form the now-defunct Clinton Township. On January 31, 1860, Orange was reincorporated as a town. Parts of the town were taken to form South Orange Township (April 1, 1861, now known as Maplewood), Fairmount (March 11, 1862, now part of West Orange), East Orange Township (March 4, 1863) and West Orange Township (April 10, 1863). On April 3, 1872, Orange was reincorporated as a city. In 1982, the city was one of four Essex County municipalities to pass a referendum to become a township, joining 11 municipalities that had already made the change, of what ultimately were more than a dozen Essex County municipalities to reclassify themselves as townships to take advantage of federal revenue sharing policies that allocated townships a greater share of government aid to municipalities on a per capita basis. The city derives its name from William III of England or William IV, Prince of Orange.

Despite the differences in the municipalities' character, Orange, East Orange, South Orange and West Orange are sometimes jointly called The Oranges.

In 2020, the township had New Jersey's 12th-highest property tax rate, with an equalized rate of 4.679% compared to 2.824% in the county as a whole and a statewide average of 2.279%.

Orange has its origins in Connecticut's New Haven Colony. In 1666, 30 of New Haven's families traveled by water to found "a town on the Passayak" River. They arrived on territory now encompassing Newark, the Oranges, and several other municipalities. The area was in the northeast portion of a land grant conveyed by King Charles II of England to his brother James, Duke of York. In 1664, James conveyed the land to two proprietors, Lord John Berkeley and Sir George Carteret. Since Carteret had been Royal Governor of the Isle of Jersey, the territory became known as "New Jersey."

Orange was initially part of the city of Newark, but it was originally known as "Newark Mountains". On June 7, 1780, the townspeople of Newark Mountains officially voted to adopt the name Orange. At the time, a significant number of people favored secession from Newark. This did not occur until November 27, 1806, when the territory now encompassing all of the Oranges was finally detached.

On April 13, 1807, the first government was elected, but not until March 13, 1860, was Orange officially incorporated as a city. Immediately, the new city began fragmenting into smaller communities, primarily because of local disputes about the costs of establishing paid police, fire, and street departments. South Orange was organized on January 26, 1861; Fairmount (later to become part of West Orange) on March 11, 1862; East Orange on March 4, 1863; and West Orange (including Fairmount) on March 14, 1863.

Orange is on the Newark and Mount-Pleasant Turnpike, the main road from Newark to Morristown, and ultimately to Easton, Pennsylvania. The town became a busy thoroughfare for travelers, and hotels abounded. Initially, the stagecoach was the primary method of transportation. Omnibuses of the Eclipse and the Morris & Newark Lines serviced Orange.