Pi Delta Theta () was a national collegiate sorority operating in the United States from February 14, 1926 until it was absorbed by Delta Sigma Epsilon in September 1941. Delta Sigma Epsilon was in turn absorbed by Delta Zeta in 1956. Pi Delta theta was a member of the Association of Education Sororities. The merger of Pi Delta Theta and Delta Sigma Epsilon was the only merger within the AES.
The Sorority publication was the Thalia, which was published twice a year and the Myrsine which was published by the ex-collegio (alumnae) chapters four times a year.
Government was vested in three entities: The national convention, the National Council and the Board of Advisers.
The badge consisted of the Greek letters ? and ? in gold with a ? set with pearls overlaying the other two letters.
Colors were white, gold with myrtle green.
Flower was the marguerite.
The chapters of Pi Delta Theta were: