
Joe Gordon, 55, who was given a two-and-a-half year jail sentence in December, was released on Tuesday, US press attache Walter Braunohler said.
Gordon, 55, a naturalised US citizen who was born Lerpong Wichaikammat, was arrested in May 2011 during a visit to Thailand.
He was found guilty of lese majeste for posting excerpts from “The King Never Smiles”, an unauthorised biography of the King that is banned in Thailand, on a Thai-language website.
The court had originally sentenced him to five years in jail, but halved it after he pleaded guilty.