Bishop Shanahan High School is located in Downingtown, Pennsylvania. It is part of the Archdiocese of Philadelphia's Catholic school system. Named after Right Rev. John W. Shanahan, the third bishop of Harrisburg, the school is the only archdiocesan high school in Chester County. Construction of the current building began in 1996. It opened in 1998, and the first class graduated from it in 1999. The school had previously been located in West Chester, Pennsylvania.