The incident occurred around 3:30pm as the couple were relaxing on the beach, despite the strong winds and heavy rain. The victim, identified as Wang Yang, 53, was crushed by the falling tree and died at the scene. Her husband, Dai Hong Jun, sustained minor injuries from a falling branch.
Police were alerted to the incident by Chalong Hospital at approximately 5:30pm.
Police confirmed Mrs Wang had suffered fatal injuries consistent with being struck by a heavy object. Her body was brought back to Phuket and taken to Vachira Phuket Hospital for a full forensic examination.
Officers said the couple had arrived on Koh Hey earlier in the day as part of a tour group.
Police are continuing to investigate the circumstances surrounding the incident. Local officials have not yet commented on whether tree maintenance or safety inspections had been carried out in the area before the storm.