Police told the court they had received a tip off that some tourists were molesting Thai girls in a bungalow in Northern Pattaya Beach in Chon Buri's Bang La Mung district.
They arrested Glen Allen Richard, 61, at his hotel room on February 17 last year.
He was accused of paying two 14yearold Thai girls Bt500 each to perform oral sex on him while he videotaped them
Richard maintained his innocence and said he was only a tourist and denied the charges.
However, the court decided evidence from witnesses and officials provided a true account of the defendant's behaviour and they had no reason to defame him. Richard's testimony was deemed unconvincing, and the court found him guilty as charged he was sentenced to a 16years prison term.
This case emerged when Police Lt Gen Montri Jamroon was alerted that four foreigners including the defendant had gathered at Pattaya Beach for lewd acts, where a middleaged woman procured Thai girls for them to videotape in return for payment from Bt500 to Bt3,000 per time.
Officials gathered evidence and then issued arrest warrants for the foreigners, who reportedly had done this many times before.
The other three defendants would be put on trial separately at a later date.