Spokesman Steve Coleman of the Port Authority of NY and New Jersey says 10 passengers were taken to a hospital.
Nearby Jamaica Hospital in Queens said seven patients were being evaluated there.
The Turkish Airlines Flight 1 reportedly encountered the turbulence about 45 minutes before landing at JFK. It will be updated.
Twenty-nine passengers are being treated for injuries sustained during major turbulence on a Turkish Airlines flight en route to John F Kennedy International Airport, authorities say.
The crew declared an emergency while the Boeing 777 was still in the air, according to the Federal Aviation Administration. Most passengers suffered bumps and bruises but a few people were sent to a hospital, authorities said, noting that at least one person had a broken leg.
Turkish Airlines Flight 001 had 326 passengers and 21 crew members on board.
The airline said it is "deeply saddened by this unfortunate experience, and closely monitors the health status of injured passengers, and is making resources available to them".
Earlier in the day, a plane operated by Canada's Air Transat made an emergency landing at another NY area airport - in Newark, New Jersey - after smoke was detected in the cargo hold, the company said.
New Jersey's Newark airport closed its runways earlier in the day after a cargo plane flying to Florida from Canada was forced to make an emergency landing.