Jacob W. Graybill (17 April 1861 – 24 March 1934) was an American politician.
He attended local schools and studied medicine at the University of Kansas.
In the years 1903 and 1904 he took additional medical courses at the Philadelphia Polyclinic School and at the University of Pennsylvania.
In addition he served as surgeon in the Kansas National Guard during the term of Governor Edward W. Hoch (1905–1909).
He joined the Republican Party and in 1908 he was a member of the electoral college which officially elected William Howard Taft to president.