St. Mary's High School was a private, Roman Catholic high school in Perth Amboy, Middlesex County, in the U.S. state of New Jersey.
St. Mary's Church was established in 1844 to serve the Irish Catholics who had settled in Perth Amboy.
A grammar school was established in 1852, followed by St. Mary High School in 1923, both staffed by the Sisters of Mercy.
[1] St. Mary's High School closed in 1981 in the wake of declining enrollment.
[2] The grammar school remained open and staffed by the Sisters of Mercy until 1986, when it was merged into Perth Amboy Catholic School.