The single-seat plane crashed at around 3 pm (0800 GMT) in the Khok Samrong district of central Lopburi province.
"The pilot could not eject himself out of the plane in time," Lopburi governor Thanakom Chongchira told AFP by telephone.
The cause of the crash, which took place near an air force training center, is under investigation.
In November nine soldiers on board an army helicopter died when their chopper crashed in northern Thailand.
In July 2011 a series of helicopter crashes in a single week forced the Thai army to ground much of its fleet.
