The news follows the Asian nation's deputy prime minister admitting that there was no way the event could proceed on its planned date of March 20-22 amid the escalating crisis surrounding the COVID-19 virus.
It follows the cancellation of the season-opening Qatar Grand Prix for the same reason, although there the Moto2 and Moto3 races will go ahead.
A statement issued by the FIM and series promoter Dorna read: "Due to the ongoing coronavirus outbreak, the decision has been taken to postpone the Thai GP.
"As the global outbreak of coronavirus continues to develop, the Thai government has communicated that it won’t be possible to hold the OR Thailand Grand Prix on its original date. The FIM, IRTA and Dorna therefore regret to announce that the event, due to be held on the 22nd of March in Buriram, has been postponed.
"The FIM, IRTA and Dorna are currently evaluating if an alternative date is possible for the event later this season. Further updates will be published as soon as available."
The cancellation of the Thailand GP means the MotoGP season is now slated to begin at the Circuit of the Americas in Austin, Texas on April 3-5.