Nanna Popham Britton (November 9, 1896 – March 21, 1991) was an American secretary who was a mistress of Warren G. Harding, the 29th President of the United States. In 1927, she revealed that her daughter, Elizabeth, had been fathered by Harding while he was serving in the United States Senate, one year before he was elected to the presidency. Her claim was open to question during her life, but was confirmed by DNA testing in 2015.