The event began at 4pm and concluded at midnight, with multi-faith ceremonies taking place from 6pm.
The event included displays explaining the devastating impact of the tsunami, which according to official statistics killed more than 5,000 people in Thailand, and an estimated 250,000 to 300,000 around the Indian Ocean rim.
Patong Mayor Chalermluck Kebsup, Kathu District Chief Sayan Chanachaiwong and Phuket Vice Governor Snith Sriwihok led the candle-lighting ceremony, with hundreds of people joining in to place their candles in their sand.
“Today marks 12 years since the tsunami and this event is to remember the victims of this disaster,” Vice Governor Snith said.
“Everyone has learned from this lesson, and people now realise what tragedies they may face and that they must be as ready possible for such situations in the future,” he said.