Gary Byrne, who guarded the Clintons for eight years when husband Bill was president, has also accused Mrs Clinton of frequent "eruptions" of anger.
His claims, out in a new book published next week called Crises of Character, have not been verified by other security personnel.
Other former and current presidential bodyguards have criticised the book, which slams the Clintons for allegedly putting their own interests before the country's and treating staff poorly.
Mr Byrne said: "The First Lady had a different sort of liveliness.
"She once threw a Bible at an agent on her detail, hitting him in the back of the head."
