The Consumer price index (CPI) rose 1.05% in January from a year earlier, quickening from the previous month and beating expectations, Commerce Ministry data showed on Thursday.
A Reuters poll had forecast the CPI would rise 0.96% year-on-year in January after December's 0.87% increase.
The headline reading was the highest in eight months and returned to the Bank of Thailand's 1%-3% target range.
The annual core inflation rate was 0.47% in January, slightly lower than a forecast of 0.50%, and against 0.49% in December.
The ministry forecast headline inflation of between 0.4% and 1.2% for 2020.