Sigma Pi is a collegiate fraternity in North America. It was founded as Tau Phi Delta at Vincennes University on February 26, 1897. In 1907, the fraternity was renamed Sigma Pi. In 1965, the fraternity absorbed the remaining chapters of Delta Kappa fraternity.
Following is a list of Sigma Pi collegiate chapters, with active chapters indicated in bold and inactive chapters and institutions in italics.
Following are the Sigma Pi alumni clubs, with active clubs indicated in bold and inactive clubs in italics.