Davis was executed by lethal injection on Wednesday after the failure of a last-ditch clemency bid. A high-profile campaign led by Amnesty International USA had struggled for years to spare him, saying his trial was deeply flawed.
"We strongly deplore that the numerous appeals for clemency were not heeded," the French foreign ministry said.
France also stressed its opposition to the death penalty "wherever it takes place and whatever the circumstances."
The statement, issued swiftly after the announcement that David was dead, underlined that "all judicial errors in the application (of the death penalty) are irreversible."
"While two-thirds of nations throughout the world today renounce this punishment, in law or in practice, this case illustrates the need to continue the fight for universal and definitive abolition of the death penalty."
The US state of Georgia executed Davis despite the international outcry over considerable doubts about his 1991 murder conviction.
Attorneys for Davis had cited new ballistics evidence and said misleading testimony had been used to convict him over the 1989 killing of off-duty policeman Mark MacPhail.
The last-ditch push to stay Davis's execution had earlier been rejected twice at the state level, and the five-member Georgia Board of Pardons and Paroles on Tuesday turned down his bid for clemency.
An unusually lengthy deliberation by the US Supreme Court delayed the process by more than four hours but the prison said Davis was pronounced dead after a lethal injection at 11:08 pm local time (0308 GMT Thursday).