The bombings and arson attacks happened after midnight and targeted convenience stores and a gas station across three provinces, lightly injuring at least seven, according to police and military statements.
No one has claimed responsibility for the attacks so far.
Provinces in southern Thailand along the border with Malaysia have seen a decades-long, low-level insurgency, in which the Thai government has battled shadowy groups seeking independence for the predominantly Muslim provinces of Pattani, Yala, Narathiwat and parts of Songkhla.
More than 7,300 people have been killed in the conflict since 2004, according to the Deep South Watch group, which monitors the violence.
Peace talks that began in 2013 have faced repeated disruptions.
Wednesday's attacks came after the Thai government earlier this year restarted discussions with the main insurgent group, the Barisan Revolusi Nasional, after a two-year hiatus due to the pandemic.
The Patani United Liberation Organisation (PULO), which was sidelined from the latest round of talks, carried out bombings during the holy Muslim month of Ramadan, claiming the dialogue is not inclusive.
The government has said it is ready to talk to all groups.
The organization's leader, Kasturi Makhota, told Reuters Wednesday's attacks have "nothing to do with PULO."