The recovery of Dr Kent Brantly and Nancy Writebol was announced by the missionary group SIM USA, which jointly ran the project in Liberia where they had been working to tackle the Ebola outbreak before catching the disease themselves.
Dr Bradley told reporters: “I am forever thankful to God for sparing my life”.
He and Ms Writebol returned to the US on 5 August and doctors say they will make a full recovery.
Both were treated with ZMapp, a drug that has only been used on a handful of patients in the current West African outbreak.
The World Health Organisation said on Wednesday that 2,473 people had been infected and 1,350 have died since the outbreak was identified in south eastern Guinea in March.
No cases of the disease have so far been confirmed outside Guinea, Sierra Leone, Liberia and Nigeria.
On Thursday South Africa announced that due to fears of the spread of the virus it would ban all travellers from Guinea, Libera and Sierra Leone from entering the country, apart from its own nationals who will be screened more thoroughly.
Travellers from Nigeria, where the outbreak has been much smaller, will be allowed entry.