https://bbc.com/news/world-asia
Rukchanok "Ice" Srinork, 28, had pleaded not guilty to posting tweets critical of the monarchy.
She has since been released on bail worth $14,000 (£11,180) pending an appeal, on the condition that she must not repeat the offence.
Ice's Move Forward party, which won this year's election, had urged reform of the lese-majeste laws.
But the unelected senate used this as the main reason for blocking the party's attempt to form a government.
On Wednesday, Ice was found guilty of insulting the monarch by a Bangkok court for two posts made before she joined Move Forward - in the first, she criticised the country's handling of the pandemic, and the second was a repost of a tweet that was said to be critical of the monarchy.
Ice will lose her seat if she eventually goes to jail.
Hers was perhaps the most dramatic of many shock victories by the young Move Forward candidates in the May general election - she won her seat in Bang Bon, a constituency near Bangkok which had been the fiefdom of one of Thailand's most powerful political clans for decades, after a no-frills campaign largely on a bicycle.
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