Prince Saud was one of the highest profile members of Saudi Arabia's ruling elite and formerly the world's longest-serving foreign minister, overseeing four decades of turbulent diplomacy for the oil-rich kingdom.
"He was a man of vast experience, personal warmth, great dignity and keen insights who served his country loyally and well," Kerry said in a statement.
"The longevity of his term in office --he served with 13 US secretaries of state-- is a sign of the universal respect with which he was viewed.
"I personally admired him greatly, valued his friendship, and appreciated his wise counsel. His legacy as a statesman and diplomat will not be forgotten," Kerry said. A statement from the Royal Court said Prince Saud, who was born in 1940, died in the United States.