John Baldwin Hawley (February 9, 1831 - May 24, 1895) was a U.S. Representative from Illinois.
Born in Hawleyville, Connecticut, Hawley moved with his parents to Carthage, Illinois, in 1833. He attended the public schools and Jacksonville College, Jacksonville, Illinois. He studied law. He was admitted to the bar in 1854 and commenced practice at Rock Island, Illinois.
Hawley was elected State's attorney in 1856 and served four years. Enlisted in the Union Army during the Civil War and served as captain of Company H, Forty-fifth Regiment, Illinois Volunteer Infantry. He was appointed postmaster of Rock Island, Illinois, in 1865, and was removed the year following by President Johnson.
Hawley was elected as a Republican to the Forty-first, Forty-second, and Forty-third Congresses (March 4, 1869-March 3, 1875). He served as chairman of the Committee on Expenditures on Public Buildings (Forty-second Congress), Committee on Claims (Forty-third Congress). He was an unsuccessful candidate for renomination in 1874. Assistant Secretary of the Treasury from December 6, 1877, until April 1880, when he resigned. He moved to Chicago, Illinois, in 1880 and resumed the practice of law. He moved to Omaha, Nebraska, in 1886. He served as general attorney for the western branches of the Northwestern Railroad Co.. He died at Hot Springs, S.Dak., May 24, 1895. He was interred in Prospect Hill Cemetery, Omaha, Nebraska.