The Order of the Knights of Pythias is an international, non-sectarian, fraternal organization that was established on February 19, 1864 in Washington D. C., by Justus H. Rathbone. Its business and operations were to be of a secret nature, and its members were required to take an oath. Established on the idea of disseminating the principles of friendship, charity and benevolence, the order was founded on the ideas of toleration of religion, obedience to law, and loyalty to the government. The organization of the Order is as follows: Worthy Chancellor, Vice-Chancellor, Venerable Patriarch, Worthy Scribe, Banker, Assistant Banker, and Assistant Scribe. Members are referred to as "brother", and participate in rituals in order to be awarded varying degrees.

It was the first fraternal order to be chartered by an Act of Congress. According to the Order, charters exist in most states and provinces, and subordinate lodges are located in many cities and towns across the United States and Canada.