The incident occurred at about 9am at the southern end of Nai Thon Beach, police confirmed.
Sakhu Police identified the missing man as Russian national Dmitrii Zakutskii, 31.
Police said they were notified of the incident at 10:14am and responded to the scene along with rescue teams from Sakhu Tambon Administration Organisation (OrBorTor) and the Kusoldharm Phuket Foundation.
At the beach, officers met a friend of Mr Zakutskii, who told police that she and a group of friends had been swimming with him when a strong wave hit and pulled him under. He did not resurface.
Search operations were immediately launched, with local rescue divers scouring the area in difficult surf conditions.
The search for Mr Zakutskii is continuing, Sakhu Police confirmed
Lifeguards and officials are continuing to urge swimmers to take extra care, as rough seas continue to pose serious risks along Phuket’s west coast, with a Phuket man and his 13-year-old nephew drowning at Bang Tao Beach over the weekend.