The accident happened at 7pm on the Loei-Khon Kaen road in Ban Noi Khiri village in Tambon Khok Khamin of Wang Saphung.
Police said the pickup appeared to lose control and crossed into the bus's lane before colliding with the Loei-Rayong bus.
The impact sent the pickup driver, Anan Insee, through the windshield. He died at the scene.
The bus driver, Natthapong Songleknok, 32, and two passengers were injured. They were sent to the the Nong Hin Hospital.