The Mississippi funeral home handling arrangements said Speakes suffered from Alzheimer's disease, the Washington Post reported. The New York Times said Speakes died Friday at his home in Cleveland, Miss.
Speakes, a deputy to Reagan's press secretary, James Brady, effectively took on the top job on March 30, 1981, when the president and Brady were shot by John Hinckley. Brady never returned to work, although he continued to hold the title of press secretary until Reagan left office.
In hundreds of White House briefings, Speakes spoke for the president during Reagan's meetings with Soviet leader Mikhail Gorbachev, which outraged many conservatives, and the Iran-Contra scandal. Reagan presented Speakes with the Presidential Citizens Medal when he resigned in 1987.
After his departure, Speakes caused an uproar when he acknowledged in a memoir, "Speaking Out," that he had manufactured Reagan quotes.
A native of Mississippi, Speakes majored in journalism at the state university and worked in the newspaper business there. He got into politics as a press secretary to U.S. Sen. James Eastland, D-Miss.
After six years with Eastland, Speakes served as a spokesman for James St. Clair, a special presidential counsel during the Watergate hearings, and later as President Gerald Ford's deputy press secretary. He spent four years in public relations, returning to the White House after Reagan's election.