The International Legal Fraternity of Phi Delta Phi, established in the year 1869 to promote a higher standard of professional ethics, is one of the oldest legal organizations in North America and in fact is the oldest legal organization in continuous existence in the United States. Founded almost nine years before the American Bar Association, Phi Delta Phi holds a unique position in the history of the North American bench, bar and law schools. During the past two decades, Phi Delta Phi's reputation as an organization devoted to legal excellence has continued to flourish internationally with new chapters in Canada, México and Europe.

Phi Delta Phi’s active chapters – called Inns after the English Inns of Court – are located at numerous law schools in North America and Europe. Since its founding in 1869, Phi Delta Phi has initiated over 195,000 members, making it the largest legal professional fraternity whose membership is limited to law students and lawyers. Unlike some other legal organizations, Phi Delta Phi does not initiate individuals who have not successfully matriculated into an accredited law school. Nevertheless, Phi Delta Phi’s published position on diversity is quite broad, and the Fraternity is committed to the elimination of discrimination based on race, color, religion, national origin, family status, sex, age, sexual orientation, handicap or disability.

More judges, American presidents, governors, senators, representatives, cabinet members, ambassadors, American Bar Association presidents, Association of American Law School presidents, and law school Deans have come from the ranks of Phi Delta Phi than from any other legal fraternity. Five of the sitting justices of the United States Supreme Court are Phi Delta Phi’s, including the Chief Justice of the United States.