Richard Wistar named the area Andorra in 1857 after the small country in the Pyrenees Mountains of Europe because he felt the topography of the two regions was similar. From colonial days this region was bisected by a major highway called The Ridge (now Ridge Avenue). The road was originally laid out in 1706 to haul lime from Collegeville to Philadelphia.
Much of the land is part of Fairmount Park, and much of the adjacent land belonged to the Houston family. The area changed from rural to more urban with the construction of houses on land that was part of the Houston estate, and the completion and modernization of Henry Avenue.
Henry Avenue was probably named for Alexander Henry, Mayor of Philadelphia from 1858-1862. His brother had married the daughter of Henry Howard Houston, who owned much of the land in Andorra.
Cathedral Road is named for the cathedral that the Episcopal Diocese started building before World War II. Construction was interrupted because of the war, and was never resumed. The constructed portion is now a chapel. Cathedral Village, a community for older adults, was built on the surrounding land.
The Andorra Branch opened on March 31, 1975 in the Andorra Shopping Center, Cathedral Road and Henry Avenue. The library was renovated in 1999 as part of the "Changing Lives" campaign, which refurbished branches. Artists Max Mason and M. Webb created the mural above the picture book section depicting the Philadelphia skyline and the Andorra Woods.