A court in the southern Thai island of Phuket has acquitted two journalists of defaming the navy and breaching the Computer Crimes Act.
Chutima Sidasathian and Australian Alan Morison, from news site Phuketwan, faced possible jail time for a line in a 2013 article on human trafficking.
The excerpt, from Reuters news agency, quoted an unnamed smuggler saying Thai naval forces made money from turning a blind eye to trafficking.
Reuters does not face any charges.
Reuters and Phuketwan were the first to examine reports of Thai involvement in the trafficking of Rohingya from Myanmar and Bangladesh.
Since then, the route the migrants take through South East Asia to get to Malaysia has been revealed to involve jungle camps and thousands of people trapped on boats in terrible conditions.
Jonathan Head, BBC News, Phuket
Chutima had good relationships with a number of Thai navy officers, who worked on the large naval base on the island. From them she heard about the large number of Rohingya Muslims from Myanmar arriving on Thailand's Andaman coast, north of Phuket.
Officers mentioned that there had been a change of policy. Instead of being detained and looked after, they were being held on offshore islands.
The navy did not want to take her there. Instead they gave her photographs, showing dozens of emaciated-looking men being made to lie down on a beach.
Read more from Jonathan Head on the journalists' pursuit of the trafficking story.
Speaking to reporters outside the court, Chutima said the verdict was "a big step for freedom of expression and freedom of the media in Thailand".
"I am happy that the court clearly said that the information we presented was useful to society and that they were not defamatory."
The trial of the journalists had sparked widespread condemnation from human rights groups and the United Nations. Amnesty International said the verdict was "a welcome move for freedom of expression".
"Vaguely worded provisions of the Computer Crime Act are being misused as a tool to silence and harass independent media," said Josef Benedict, Amnesty International's South East Asia campaigns director.
A crackdown in May on human trafficking by Thai authorities has led to dozens of arrests including local officials and a senior army general.