Perth Amboy is a city in Middlesex County, New Jersey, United States. The City of Perth Amboy is part of the New York metropolitan area. As of the 2010 United States Census, the city's population was 50,814, reflecting an increase of 3,511 (+7.4%) from the 47,303 counted in the 2000 Census, which had in turn increased by 5,336 (+12.7%) from the 41,967 counted in the 1990 Census. The Census Bureau's Population Estimates Program calculated that the city's population was 51,390 in 2019, ranking the city the 758th-most-populous in the country. Perth Amboy has a Hispanic majority population. In the 2010 census, persons of "Hispanic, Latino or Spanish origin" made up 78.1% of the population, the second-highest in the state, behind Union City at 84.7%. Perth Amboy is known as the "City by the Bay", referring to its location adjoining Raritan Bay.
The earliest residents of the area were the Lenape Native Americans, who called the point on which the city lies "Ompoge". Perth Amboy was settled in 1683 by Scottish colonists and was called "New Perth" after James Drummond, 4th Earl of Perth; the native name was eventually corrupted and the two names were merged. Perth Amboy was formed by Royal charter in 1718, and the New Jersey Legislature reaffirmed its status in 1784, after independence. The city was a capital of the Province of New Jersey from 1686 to 1776.