Phi Kappa Tau (ΦΚΤ), commonly known as Phi Tau (/faɪ tɔː/), is a collegiate fraternity located in the United States. The fraternity was founded in 1906. As of November 2022, the fraternity has 161 chartered chapters, 79 active chapters, 6 Associate chapters and about 3,500 collegiate members. SeriousFun Children's Network, founded by Beta chapter alumnus Paul Newman, is Phi Kappa Tau's National Philanthropy. According to its Constitution, Phi Kappa Tau is one of the few social fraternities that can accept graduate students as well as undergraduates.