Payson Jackson Treat (November 12, 1879 – June 15, 1972) was an American Japanologist.

He was born in New York City on November 12, 1879,[1] and attended Wesleyan University as an undergraduate.

[2] He started teaching at Stanford University in 1905,[1] and was appointed a professor of history there in 1906—the first professorship in Far Eastern history at an American university.

[2] Treat received a doctorate at Stanford in 1910,[1] working on the history of the American land system as a student of Max Farrand.

Until his death, Treat maintained an index card file relating the names and children of over 7,000 of his students.