Several carriages from the Amtrak Empire Builder passenger service derailed at about 16:00 local time (22:00 GMT) near the town of Joplin.
Images on social media show train cars on their sides and luggage strewn on the ground with people standing nearby.
Amtrak said there were some 141 passengers and 16 crew aboard the Chicago to Seattle service.
Passenger Megan Vandervest, who was heading to see a friend in Seattle, told the New York Times she was woken up by the derailment, which felt like "extreme turbulence on a plane."
