Phi Lambda Theta (ΦΛΘ) was a social fraternity founded at Pennsylvania State College in 1920 for students who belonged to the Independent Order of Odd Fellows.

November 18, 1920, is designated as Founders' Day as on that date the body first met as an organization officially recognized by the Pennsylvania College college board on fraternity affairs.

Modification of the non-collegiate Odd Fellows lodge requirement was effected on September 13, 1922, and all affiliations and subsidiary connections with the Odd Fellows were severed in January 1924.

In 1930, Phi Lambda Theta was admitted to Junior membership in the North American Interfraternity Conference.

[2] Rather than a coordinated merger strategy, the dissolution of Phi Lambda Theta appears to have been a sudden rush for the door, late in the Great Depression.