William Gordon Brantley was an American politician and lawyer. Brantley was born in Blackshear, Georgia. He attended the University of Georgia in Athens, gained admission to the state bar in 1881, and began practicing law in Blackshear.

Brantley was elected to the Georgia State House of Representatives in 1884 and 1885 and the Georgia Senate in 1886 and 1887. In 1888, he became solicitor general of the Brunswick, Georgia Circuit Court. In 1896, Brantley successfully ran for the United States House of Representatives and was re-elected seven more terms until deciding not to run for re-election in 1912. Brantley served as a delegate the Democratic National Convention in that year.

After his congressional service, Brantley remained in Washington, D.C. to practice law. He died in that city in 1934 and was buried in Blackshear Cemetery in the town of his birth.