[1] His father, Day Otis Kellogg, was a professor of literature at the University of Kansas and editor of the American edition of the Encyclopædia Britannica.

In 1895 Oliver Kellogg began his undergraduate study at Princeton University, where he earned his master's degree in 1900.

With a John S. Kennedy stipend he first studied at the Humboldt University of Berlin and then in 1901/1902 at Georg-August-Universität Göttingen.

At Göttingen in 1902 he earned his PhD with a thesis Zur Theorie der Integralgleichungen und des Dirichlet'schen Prinzips under the direction of David Hilbert.

In World War I he was a scientific advisor at the Coast Guard Academy in New London, Connecticut, where he worked on submarine detection.