Frederick John Teggart (1870–1946) was an Irish-American historian and social scientist, known for work on the history of civilizations.

He then worked as a librarian, first at Stanford and then at the Mechanics-Mercantile Library in San Francisco.

A full professor in 1925, he retired in 1940, although he remained actively engaged in research until shortly before his death.

When Arnold J. Toynbee was still forming his concept for A Study of History he read some of Teggart's works.

his books at a time when, though I knew what I wanted to do, I still could not find the right starting point.