The accident occurred at about 7am near the Phuvaree Resort, said Lt Col Chanarong Prakongkeo of Patong Police.
Rescue workers from the Kusoldharm Phuket Foundation arrived to find the rider, identified as Bill Bahadur, 62, lying dead at the roadside. He was wearing a blue raincoat, and a helmet, at the time of the crash.
Nearby, officers found a black Honda motorbike with severe front-end damage, along with a white Isuzu trailer truck bearing Songkhla licence plates. The truck was confirmed to belong to Chusin Nuchu, 45.
Police said Mr Bahadur had been riding from the Pearl Roundabout towards Karon when he slammed into the rear of the truck, which was parked at the roadside while it was raining.
A forensic doctor from Vachira Phuket Hospital examined the body at the scene before it was transferred to the hospital for further examination. Relatives of the deceased are being informed, police noted.
Police have yet to speculate the cause of the accident, but did note the heavy rain and wet road at the time of the crash.