District 11 (often referenced with the Roman Numerals District XI) of the Pennsylvania Interscholastic Athletic Association (PIAA) is an interscholastic athletic association in eastern Pennsylvania. District XI is one of the PIAA's 12 districts and comprises high schools mostly within the Lehigh Valley and a few surrounding counties. Member schools are categorized by enrollment into classifications, differing in each of the various sports, including: A, AA, AAA, AAAA, AAAAA, and AAAAAA.