The 1966 Georgia gubernatorial election was held in the U.S. state on November 8, 1966. After an election that exposed divisions within the Georgia Democratic Party (giving the Georgia Republican Party a shot at the Governor's Mansion for the first time in the twentieth century), segregationist Democrat Lester Maddox was elected Governor of Georgia. The voting also brought future President Jimmy Carter to statewide prominence for the first time. The election was the closest in Georgia gubernatorial history; Republican candidate Bo Callaway won a plurality of the popular vote, but lost the contingent election in the Georgia General Assembly to Maddox. It was also the first time since 1916 that the Republican Party contested a gubernatorial election. If Callaway had won the contingent election or a majority of the popular vote, he would have become the only Republican governor of Georgia in the 20th century.

As of 2022, this is the last time that Dougherty, Macon, Randolph, Richmond, Stewart, and Talbot counties voted for the Republican candidate for governor, and the last time that Liberty County did not vote for the Democratic candidate.

Former Governor Ernest Vandiver was considered the favorite to return to his former job (although governors could not then succeed themselves, they could run again after leaving office), but he dropped out of the race because of health problems. That opened the door for former Governor Ellis Arnall, former Lieutenant Governor Garland T. Byrd, state Senator Jimmy Carter, and two segregationist businessmen, Lester Maddox and James H. Gray Sr., to run for the Democratic nomination.

Gray, a Massachusetts native, publisher of the Albany Herald and founder of what is now Gray Television, was a former Georgia Democratic state chairman who defended segregation in his northern accent before the 1960 Democratic National Convention in Los Angeles. In the primary race, Maddox had often called upon Gray to leave the race, having said that his opponent was "going down like the Titanic". Gray remained in the race and finished fourth in the primary. He declared neutrality in the Maddox-Arnall runoff election, not openly supporting either candidate. However, one of Gray's associates, Roy V. Harris of Augusta, a member of the Georgia State Board of Regents, supported Maddox over Arnall. Gray supporters attempted to entice Maddox to leave the race with a $100,000 payment. Gray denied involvement in the scheme but would not, on Maddox's request, take a lie detector test.

The primary was held on September 13, 1966.

Pursuant to Georgia law, as no candidate received a majority of votes in the primary, a runoff was held on September 27.

State House Speaker George T. Smith was the Democratic nominee for Lieutenant Governor of Georgia, after he defeated incumbent Peter Zack Geer in the primary. He went on to win the general election.

The Republican nominee was U.S. Representative Bo Callaway. He was the first Republican Representative from Georgia since Reconstruction.