Samuel Eliot Morison was born July 9, 1887, in Boston, Massachusetts, to John Holmes Morison (1856-1911) and Emily Marshall (Eliot) Morison (1857-1925).
Morison attended Noble and Greenough School (1897-1901) and St. Paul's (1901-1903) prior to entering Harvard University, where he was a member of the Phoenix S K Club.