Beta Theta Pi (ΒΘΠ) is a social collegiate fraternity that was founded in 1839 at Miami University in Oxford, Ohio, USA, where it is part of the Miami Triad which includes Phi Delta Theta and Sigma Chi. Beta, as it is nicknamed, was the first college fraternity to be founded west of the Allegheny Mountains, and it has 120 active chapters and colonies in the United States and Canada. Over 190,000 (2010) members have been initiated worldwide, with ~133,000 of those living. Beta Theta Pi currently has more than 5,500 undergraduate members. Beta's Administrative Office is located at 5134 Bonham Road, Oxford, Ohio. In 2006, the driveway up to the administrative office was renamed "Lugar-Bates Drive" in appreciation for the work that Senator Richard Lugar Denison '54 and Bert Bates Missouri '56 performed in the $20 million "Upon These Principles" capital campaign.

The eight founders in the order in which their names appear in the minutes were:

"of ever honored memory"

— The "Founders' Paragraph"

The purpose of Beta Theta Pi was laid out publicly in 1879, when Beta Theta Pi became the first college fraternity to publish its constitution. The Fraternity continues to guard certain secrets which are reserved for its members; however, it offers wide knowledge of the objects and aspirations of Beta Theta Pi. The Code of Beta Theta Pi lays out the objects of the Fraternity as follows:

-The Code of Beta Theta Pi, Article 1, Section 2

-Willis O. Robb, Ohio Wesleyan 1879

Acacia • Alpha Gamma Rho • Alpha Gamma Sigma • Alpha Delta Gamma • Alpha Delta Phi • Alpha Epsilon Pi • Alpha Kappa Lambda • Alpha Sigma Phi • Alpha Tau Omega • Alpha Phi Alpha • Alpha Phi Delta • Alpha Chi Rho • Beta Sigma Psi • Beta Theta Pi • Beta Chi Theta • Delta Kappa Epsilon • Delta Sigma Phi • Delta Tau Delta • Delta Upsilon • Delta Phi • Delta Chi • Delta Psi • FarmHouse • Zeta Beta Tau • Zeta Psi • Theta Delta Chi • Theta Xi • Theta Chi • Iota Nu Delta • Iota Phi Theta • Kappa Alpha Order • Kappa Alpha Psi • Kappa Alpha Society • Kappa Delta Rho • Kappa Delta Phi • Lambda Theta Phi • Lambda Sigma Upsilon • Lambda Phi Epsilon • Lambda Chi Alpha • Nu Alpha Kappa • Pi Kappa Alpha • Pi Kappa Phi • Pi Lambda Phi • Sigma Alpha Epsilon • Sigma Alpha Mu • Sigma Beta Rho • Sigma Lambda Beta • Sigma Nu • Sigma Pi • Sigma Tau Gamma • Sigma Phi Delta • Sigma Phi Epsilon • Sigma Phi Society • Sigma Chi • Tau Delta Phi • Tau Epsilon Phi • Tau Kappa Epsilon • Triangle • Phi Beta Sigma • Phi Gamma Delta • Phi Iota Alpha • Phi Kappa Theta • Phi Kappa Sigma • Phi Kappa Tau • Phi Kappa Psi • Phi Lambda Chi • Phi Mu Delta • Phi Sigma Kappa • Phi Sigma Phi • Chi Phi • Chi Psi • Psi Upsilon • Omega Delta Phi