George Mortimer Bibb (October 30, 1776–April 14, 1859) was an American politician.

Bibb was born in Prince Edward County, Virginia, graduated from Hampden-Sidney College and the College of William & Mary, then studied law. He was admitted to the bar and practiced law in Virginia and Lexington, Kentucky. After making a permanent move to Kentucky he was elected to the Kentucky House of Representatives in 1806, 1810 and again in 1817. He was appointed a judge of the Kentucky Court of Appeals in 1808 and then chief justice through 1810.

In 1811 he was elected to the United States Senate from Kentucky and served until 1814 when he again returned to Lexington to work as a lawyer. He moved to Frankfort, Kentucky in 1816 and was again named Chief Justice of the Kentucky Court of Appeals in 1827, serving for a year.

He was re-elected to the United States Senate in 1829 and served as a Jacksonian Democrat through 1835. During the 21st Congress he was chairman of the U.S. Senate Committee on Post Office and Post Roads.

He was chancellor of the Louisville Chancery Court from 1835 through 1844 and in 1844 became President John Tyler's fourth United States Secretary of the Treasury serving through 1845.

He was a very aged man when he assumed his Treasury position, dressing "in antique style, with kneebreeches." Bibb's Annual Report on the State of the Finances for 1844 consisted of an elaborate compilation of statistics detailing the financial history of the nation since 1789. In addition, he presented a solid argument for the establishment of a "sinking fund," accumulated through regular deposits and used to pay the interest and principal on the national debt. Bibb advocated using Treasury surplus revenue from customs and internal revenue collection to supply the sinking fund. Such a fund had been used effectively to reduce the deficit from 1789 to 1835, but Bibb was unable to revive it.

After this he was a lawyer in Washington, D.C. and an assistant in the U.S. Attorney General's office.

He died in Georgetown, D.C. in 1859; his burial location is unknown.