The 28-year-old was found guilty of posting insulting messages about the monarchy on Facebook between 2010 and 2011, said a court official from the northeastern province of Ubon Ratchathani, without giving further details.
King Bhumibol Adulyadej, 86, is revered by many Thais and protected by tough royal defamation laws.
Under the strict lese majeste rules anyone convicted of insulting the king, queen, heir or regent faces up to 15 years in prison on each count.
But after admitting to all charges his sentence was reduced to 15 years in jail.
"The suspect had repeatedly committed wrongdoings and in this case the judge has sentenced him with minimum penalties for both charges," said the court official.
Since seizing power in Thailand in May, the army has clamped down on any opposition to its takeover, with a crackdown on perceived slurs against the royals at the heart of its stepped-up online surveillance operations.
Before the coup, calls for reform of the lese majeste laws had grown following several high-profile convictions.
But academics urging greater debate are among hundreds of people who were summoned by the junta and temporarily detained in secret locations.
You’ve reached your limit of {{free_limit}} free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Exclusive premium stories online
Over 30 premium stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app
