The Philadelphia Art Alliance is a multidisciplinary arts center located in Philadelphia, Pennsylvania, in the Rittenhouse Square neighborhood. It is the oldest multidisciplinary arts center in the United States for visual, literary and performing arts. Founded in 1915 by theater aficionado and philanthropist Christine Wetherill Stevenson, the institution hosts art exhibits, theater and music workshops, poetry readings, lectures, concerts and recitals.
The Alliance is housed in the historic Wetherill mansion, which was designed and constructed in 1906 by Charles Klauder. The building was listed on the Philadelphia Register of Historic Places on April 28, 1970, and is also listed on the National Register of Historic Places as part of the Rittenhouse National Register Historic District.