Alpha Delta Pi (ΑΔΠ), commonly known as ADPi (pronounced "ay-dee-pye"), is an International Panhellenic sorority founded on May 15, 1851, at Wesleyan College in Macon, Georgia. It is the oldest secret society for women.
Alpha Delta Pi is a member of the National Panhellenic Conference. The sorority's national philanthropic partner is the Ronald McDonald House Charities. Its executive office is located in Atlanta, Georgia.