American Samoa's population stands at 57,436, an increase of more than 2000 people from the last survey in 2010.
The figures are revealed in the Department of Statistics' population and housing survey, which was carried out in April and May last year.
It says there are more females than males in American Samoa, and the median age is 25.3 years - much lower than that for the rest of the United States.
Samoans are the largest ethnic group, making up 93 percent of the population, followed by Tongans.
About half of all people in American Samoa have a mother or father born in neighbouring Samoa, which the survey says highlights the strong link between the two Samoas.
