The father of the one-year-old girl, who was driving the car, also suffered serious injuries in the crash.
Thalang Police were notified of an accident at Saladang Intersection on Thepkrassatri Rd southbound at 11:15pm on Saturday night.
Capt Eakkasak Kwanwan of Thalang Police arrived at the scene, 50m from a U-turn, together with Kusoldharm rescue workers.
At the scene police found a white bus with its front and right side damaged and nearby was a dark coloured Chevrolet car with its left side damaged.
Rescue workers had to use a hydraulic cutter to free driver Pradit Robroo, 24, Kanlaya Meanbut, 18, and her one-year-old daughter Kornkamon Robroo.
Ms Kanlaya and Kornkamon had suffered serious injuries and were unconscious.
Mr Pradit and Ms Kanlaya were taken to Thalang Hospital before being transferred to Vachira Phuket Hospital in Phuket Town.
Kornkamon, the one-year-old-girl, was pronounced dead at Thalang hospital and her mother, Ms Kanlaya, was also later pronounced dead at Vachira Phuket Hospital.
Capt Eakkasak said, “After we checked CCTV nearby we found that a car was heading from Thepkrassatri Rd northbound. At the intersection the car slowed down at a red light and waited to make a U-turn.
"When the light turned yellow then red, the car immediately made a u-turn. While a bus, driven by Boonyong Linla, 42, speed through the red light and collided with the car.
“Mr Boonyong was taken to Thalang Police station and charged with reckless driving causing injury and death,” Capt Eakkasak added.