Freeport is a borough in Armstrong County, Pennsylvania, United States. It is situated along the Allegheny River in the southwestern corner of the county. The population was 1,736 at the 2020 census.

Armstrong County is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population was 65,558. The county seat is Kittanning. The county was organized on March 12, 1800, from parts of Allegheny, Westmoreland and Lycoming Counties. It was named in honor of John Armstrong, who represented Pennsylvania in the Continental Congress and served as a major general during the Revolutionary War.