The Priestley-Forsyth Memorial Library, also known as the Dr. Joseph Priestley House or Cross Keys Inn, in Northumberland, Pennsylvania, was listed on the National Register of Historic Places in 1981.

History and architectural features

This historic library building was originally erected and operated as an inn in 1820. It was purchased circa 1880 by the theologian and scientist Joseph Priestley's great-grandson, Dr. Joseph Priestley, who used it as a home and medical office. It was converted into a public library circa 1925.

It is located at 100 King Street in Northumberland, at the corner of Front Street (Route 11). It is within the Northumberland Historic District, which also includes the Joseph Priestley House.