He was flown by helicopter to the Geneva University Hospital "where he is currently being evaluated" following the accident in Scionzier, France, near Chamonix in the French Alps, a statement said, adding that Kerry, 71, had "likely suffered a leg injury".
The accident occurred at around 9:40 am (0740 GMT), the statement said.
"Paramedics and a physician were on the scene with the secretary's motorcade at the time of the accident," it said, adding that Kerry "is stable and... did not lose consciousness."
Kerry held talks Saturday in Geneva with his Iranian counterpart Mohammad Javad Zarif in efforts to secure a nuclear deal ahead of a June 30 deadline.
The talks did not go into a second day as planned after Tehran rejected a key Western demand for site inspections, according to AFP.