The 62 men, six women and 28 children were found in a long-tailed boat floating north of Koh Ra in tambon Koh Phra Thong of Takua Pa district.
All of them were in exhausted condition and some were sick.
The migrants were arrested by a team made up of border patrol, marine police and administrative officers after they had been alerted to the suspicious vessel.
The refugees had left Arakan State in western Myanmar on Jan 1, aiming to come ashore in either Thailand or Malaysia. They wanted to look for jobs after their houses and property had been occupied by Myanmar authorities, Spring News reported, quoting local authorities.
The illegal migrants, who are in poor physical condition, had brought only fresh water and uncooked rice with them during the 26-day sea journey.
Officials gave them food and water before sending them to a temporary shelter in Khura Buri district, where they later received health checkups by medical personnel. Doctors gave saline solution to 12 sickened Rohingya.
Foreign Minister Surapong Tovichakchaikul said earlier that a total of 1,390 illegal Rohingya migrants including children were currently in authorities’ custody. Saturday’s arrest has raised the total to almost 1,500.
Mr Surapong announced on Friday that Thailand would shelter the Royingya for six months and seek talks with Myanmar and other countries to settle the fate of the illegal migrants.
The decision was reached in talks between the Foreign Ministry and other security agencies amid growing calls for Thailand not to turn the migrants away after they have entered the kingdom.
The government will set aside a budget of 12 million baht or 75 baht a day for each of the migrants for a daily allowance.
Bangkok will hold talks with international agencies including the United Nations High Commission for Refugees, the International Organisation for Migration, and the International Committee of the Red Cross. It would also approach third countries willing to give the migrants a new home, the minister said.
The Rohingya are a Muslim minority in Myanmar. Most of them live in Rakhine state in the west and face brutal treatment from Myanmar authorities, including the reluctance of Nay Pyi Taw to grant them citizenship.
The current crisis came to light after authorities rounded up more than 900 Rohingya in separate operations in Songkhla as they were waiting to be sent to work in Malaysia.
A police investigation found some Thai army soldiers were linked to trafficking them from Myanmar to Malaysia through Thailand. Two of them based in the southernmost region are being probed in connection with the issue.