The Philadelphia Orchestra is a symphony orchestra based in Philadelphia, Pennsylvania, in the United States. One of the "Big Five" American orchestras, it was founded in 1900. The orchestra's home is the Kimmel Center for the Performing Arts, where it performs its subscription concerts, numbering over 130, in Verizon Hall.

From 1900 to 2001, the Philadelphia Orchestra gave its concerts at the Academy of Music. The orchestra continues to own the Academy, and returns there one week per year that includes the Academy of Music's annual gala concert and concerts for school children. The Philadelphia Orchestra's summer home is the Mann Center for the Performing Arts. It also has summer residencies at the Saratoga Performing Arts Center, and since July 2007 at the Bravo! Vail Valley Festival in Vail, Colorado. The orchestra also performs an annual series of concerts at Carnegie Hall.

Since 2008, the orchestra's Chief Conductor is Charles Dutoit. Wolfgang Sawallisch, music director from 1993 to 2003, is the orchestra's Conductor Laureate. Yannick Nézet-Séguin is the orchestra's Music Director Designate, as of June 2010, and is scheduled to become the orchestra's eighth Music Director with the 2012-2013 season.

On April 16, 2011, the board of the 111-year-old Philharmonic voted to file for Chapter 11 reorganization, making it the first major U.S. orchestra to file for bankruptcy.