| Liberty School No. 4, Friendship Building | |
| Location: | 5501 Friendship Ave., Pittsburgh, Pennsylvania |
| Coordinates: | 40.4622°N -79.9358°W |
| Built: | 1899 |
| Architect: | Bartberger, Charles M. |
| Architecture: | Beaux Arts |
| Added: | September 30, 1986 |
| Refnum: | 86002684 |
| Designated Other1 Name: | City of Pittsburgh Historic Structure |
| Designated Other1 Date: | November 30, 1999[1] |
| Designated Other1 Abbr: | CPHS |
| Designated Other1 Link: | List of City of Pittsburgh historic designations |
| Designated Other1 Color: | black |
| Designated Other1 Textcolor: | gold |
| Designated Other2: | PHLF |
| Designated Other2 Date: | 1998[2] |
The Friendship School, also known as Liberty School No. 4, is a school building built in 1899 in the Friendship neighborhood of Pittsburgh, Pennsylvania. It now houses Pittsburgh Montessori School PreK-5, a public Montessori Magnet School that is part of the Pittsburgh Public School District. It was listed on the National Register of Historic Places in 1986.