| County: | Petersburg Borough |
| State: | Alaska |
| Ex Image: | Five Finger Light House 49.jpg |
| Ex Image Size: | 220px |
| Founded Year: | 2013[1] |
| Founded Date: | January 3 |
| Seat Wl: | Petersburg |
| Largest City Wl: | Petersburg |
| City Type: | CDP |
| Area Total Sq Mi: | 3829 |
| Population As Of: | 2020 |
| Population Total: | 3360 |
| Population Density Sq Mi: | auto |
| Web: | https://www.petersburgak.gov/ |
| District: | At-large |
| Time Zone: | Alaska |
| Named For: | Petersburg |
Petersburg Borough is a borough in the U.S. state of Alaska. According to the 2020 census, the population was 3,398.[2] The borough seat is Petersburg.[3]
When the borough was incorporated in 2013, it took area from the Hoonah-Angoon Census Area and the former Petersburg Census Area. The remaining portion of Petersburg Census Area (including Kake) was added to Prince of Wales-Hyder Census Area. Petersburg Census Area was created in 2008 from the remaining portion of Wrangell-Petersburg Census Area upon the incorporation of the City and Borough of Wrangell.[4]
Located in central Southeast Alaska, the Petersburg Borough encompasses approximately 3,829 square miles (2,921 square miles of land, 908 square miles of water).
Petersburg is strongly Republican, having last been carried by a Democrat in 1968.
As of the 2020 census, there were 3,398 people living in the borough. The population density was 0.89/mi2. There were 1,718 housing units. The racial makeup of the borough was 2,870 White, 92 Black or African American, 483 Native American, 209 Asian, 58 Pacific Islander, and 206 from other races. 164 of the population were Hispanic or Latino of any race.