Phi Alpha Theta (ΦΑΘ) is an American honor society for undergraduate and graduate students and professors of history.

Nels Andrew N. Cleven, a professor of history at the University of Arkansas, played an active role in fraternity and sorority social affairs and became inspired by the structure of those groups to create a society for historical study.

[1] The description of the society's emblem is precise: The emblem of the Society is a gold disc, "with the edge milled to represent a serpent's body, the forepart of the serpent's body being on the right side of the badge, and the eye shall be represented by a red jewel."

On the face is a raised six-pointed star faced with black, "and bearing in gold the Greek letters Phi Alpha Theta horizontally across the middle, and the points bearing the Greek letters psi, pi, alpha, lambda, upsilon, and psi [Ψ, Π, Α, Λ, Υ, and Ψ again] in clockwise rotation beginning at the uppermost point.

[4] The society's national headquarters and the journal's editorial offices are located at the University of South Florida.