Otto Tremont Bannard was born on April 28, 1854 in Brooklyn, New York,[REF] the son of John Winslow Bannard (1822-1911) and his wife Eliza Landon Stone (1821-1903) [REF].
Otto studied in the preparatory department of Beloit College before attending Yale University, where he was a member of the senior society Skull and Bones, and from which he was graduated with a B.A. in 1876.