Hiram Barber Jr. (March 24, 1835 – August 5, 1924) was a U.S. Representative from Illinois.

Born in Queensbury, New York, Barber moved to Horicon, Wisconsin in 1846.

He moved to Chicago, Illinois, and resumed the practice of law in 1866.

He was receiver of the land office at Mitchell, South Dakota from 1881 to 1888.

He served as master in chancery of the Cook County Superior Court from 1891 to 1914.