New Castle Armory is a historic National Guard armory located at Shenango Township, Lawrence County, Pennsylvania. It was built in 1938, and is an "I"-plan stone building consisting of a one- to two-story administration building, with a connected riding hall and former stable building. It was built as a Federal public works project and is in the Art Deco style.

It was added to the National Register of Historic Places in 1991.