Richard Pretlow Ernst (February 28, 1858 – April 13, 1934) was a U.S.

Born in 1858, Ernst graduated from Centre College in 1878 and earned his law degree from the Cincinnati Law School in 1880.

That year, he was admitted to the bar and began practicing law in Cincinnati, Ohio, and Covington, Kentucky.

He served on the Covington city council from 1888 to 1892 and ran (unsuccessfully) for election to Congress in 1896.

He was defeated in his bid for re-election in 1926 by future Vice President Alben W. Barkley and returned to practicing law in Cincinnati.