Robert Emmett Jeffery Jr. (January 30, 1875 – May 19, 1935) was an American lawyer, politician, and diplomat who served as the United States ambassador to Uruguay from 1915 to 1921.

Jeffery was born in Mount Olive, Izard County, Arkansas, the oldest of 10 siblings.

A childhood friend of Congressman William Allan Oldfield, Jeffery was recommended for a position in the Wilson administration.

He was appointed to serve as ambassador to Uruguay in 1915 and remained in the position until 1921.

[2][3] After returning to Arkansas, Jeffery became an advocate for education in rural communities.