Jacob Erastus Davis (October 31, 1905 – February 28, 2003) was a Democratic member of the U.S. House of Representatives from Ohio.

He worked as a lawyer in private practice, and served as prosecuting attorney of Pike County, Ohio, from 1931 to 1935.

He was a member of the Ohio House of Representatives from 1935 to 1937, serving as speaker pro tempore and majority floor leader in 1937.

He was common pleas judge of Pike County, Ohio, from 1937 to 1940.

Interment in Spring Grove Mausoleum in Cincinnati, Ohio.