Five anti-government demonstrators who had been accused of attempting to harm the Queen were cleared by a Thai court.
The case is related to 2020 pro-democracy demonstrations in Bangkok, where protesters blocked Queen Suthida's motorcade.
The court determined that there was no intent on the part of the defendants to prevent the royal convoy from passing through the rally.
The monarchy is revered in Thailand, and anyone who criticizes it faces a lengthy prison sentence.
Lese majeste is a contentious law that forbids insulting the monarchy and is one of the strictest in the world. Anyone found to have broken the law could spend up to 15 years behind bars. .
The United Nations has repeatedly urged Thailand to change the law because critics claim that the military-backed government uses it to stifle free speech.
For the first time, young activists demanded a number of royal reforms, including changes to the lese majeste law, during the youth-led protests that went on into 2021.
The defendants were accused of violating a different, rarely used law that prohibits attempted violence against senior royals and carries a minimum sentence of 16 years in prison.
A death sentence or a life sentence may be imposed for more serious infractions of this law.
The protesters, according to the prosecution, deliberately broke away from the demonstrations to block the path of the royal motorcade carrying the Queen because they knew it was going to pass through the area.
They were charged in accordance with Article 110 of the Criminal Code of Thailand, which forbids anyone from endangering the freedom of the Queen, the heir apparent, or the regent.
Bangkok's Criminal Court, however, came to the conclusion that there had been no explicit announcement to the public about a motorcade in the area prior to its arrival, and it was unlikely the protesters would have known.
Following the decision, one of the activists, Bunkueanun Paothong, told the news agency Reuters: "I'm really glad. We have fought this and maintained our innocence.