This is a list of the National Register of Historic Places listings in Armstrong County, Pennsylvania.

This is intended to be a complete list of the properties and districts on the National Register of Historic Places in Armstrong County, Pennsylvania, United States. The locations of National Register properties and districts for which the latitude and longitude coordinates are included below, may be seen in a map.^[1]

There are 14 properties and districts listed on the National Register in the county.

          This National Park Service list is complete through NPS recent listings posted February 9, 2024.^[2]

Current listings

[3]	Name on the Register	Image	Date listed[4]	Location	City or town	Description
1	Allegheny River Lock and Dam No. 5		April 21, 2000 (#00000399)	830 River Road above Freeport 40°41′09″N 79°39′59″W / 40.685833°N 79.666389°W / 40.685833; -79.666389 (Allegheny River Lock and Dam No. 5)	Gilpin and South Buffalo Townships
2	Allegheny River Lock and Dam No. 6		April 21, 2000 (#00000400)	1258 River Road above Freeport 40°43′05″N 79°34′46″W / 40.718056°N 79.579444°W / 40.718056; -79.579444 (Allegheny River Lock and Dam No. 6)	Bethel and South Buffalo Townships
3	Allegheny River Lock and Dam No. 7		April 21, 2000 (#00000401)	Along Pennsylvania Route 4023, 0.6 miles (0.97 km) north of Kittanning Bridge 40°49′16″N 79°31′44″W / 40.821111°N 79.528889°W / 40.821111; -79.528889 (Allegheny River Lock and Dam No. 7)	East Franklin Township and Kittanning
4	Allegheny River Lock and Dam No. 8		April 21, 2000 (#00000402)	Along Pennsylvania Route 1033, 1.5 miles (2.4 km) south of Templeton 40°53′48″N 79°28′48″W / 40.896667°N 79.48°W / 40.896667; -79.48 (Allegheny River Lock and Dam No. 8)	Boggs and Washington Townships
5	Allegheny River Lock and Dam No. 9		April 21, 2000 (#00000403)	Terminus of Pennsylvania Route 1004, 0.2 miles (0.32 km) north of Township Route 488 40°57′17″N 79°32′50″W / 40.954722°N 79.547222°W / 40.954722; -79.547222 (Allegheny River Lock and Dam No. 9)	Madison and Washington Townships
6	Armstrong County Courthouse and Jail	More images	November 1, 1981 (#81000526)	East Market Street 40°48′59″N 79°31′00″W / 40.816389°N 79.516667°W / 40.816389; -79.516667 (Armstrong County Courthouse and Jail)	Kittanning
7	Bradys Bend Iron Company Furnaces	More images	August 11, 1980 (#80003407)	Pennsylvania Route 68 in Bradys Bend 40°59′55″N 79°37′34″W / 40.998611°N 79.626111°W / 40.998611; -79.626111 (Bradys Bend Iron Company Furnaces)	Bradys Bend Township
8	Bridge between Madison and Mahoning Townships		June 22, 1988 (#88000798)	Legislative Route 03178 over Mahoning Creek near Deanville 40°55′52″N 79°23′18″W / 40.931111°N 79.388333°W / 40.931111; -79.388333 (Bridge between Madison and Mahoning Townships)	Madison and Mahoning Townships
9	Colwell Cut Viaduct		June 22, 1988 (#88000796)	Legislative Route 66 over the Pittsburg and Shawmut Railroad southwest of Seminole 40°56′13″N 79°21′47″W / 40.936944°N 79.363056°W / 40.936944; -79.363056 (Colwell Cut Viaduct)	Mahoning Township
10	Drake Log Cabin		March 3, 1983 (#83002214)	Williams Alley 40°34′45″N 79°33′55″W / 40.579056°N 79.565278°W / 40.579056; -79.565278 (Drake Log Cabin)	Apollo
11	Ford City Armory		December 22, 1989 (#89002074)	301 Tenth Street 40°46′18″N 79°31′55″W / 40.771667°N 79.531944°W / 40.771667; -79.531944 (Ford City Armory)	Ford City
12	Thomas Marshall House		April 22, 1976 (#76001602)	State Street 40°52′50″N 79°14′34″W / 40.880556°N 79.242778°W / 40.880556; -79.242778 (Thomas Marshall House)	Dayton
13	St. Patrick's Roman Catholic Church		March 21, 1978 (#78002340)	West of Cowansville off Pennsylvania Route 268 40°53′45″N 79°40′37″W / 40.895833°N 79.676944°W / 40.895833; -79.676944 (St. Patrick's Roman Catholic Church)	Sugarcreek Township
14	St. Stephen's Church		June 30, 1980 (#80003408)	Pennsylvania Route 68 in Bradys Bend 40°59′40″N 79°37′51″W / 40.994444°N 79.630833°W / 40.994444; -79.630833 (St. Stephen's Church)	Bradys Bend Township